Tourmaline, "The Electric Stone", is exploited in hundreds of patents. Here are several select patents and articles of especial interest in regard to the production of electricity by tourmaline, and agriculture.

See also : T.T. BROWN / Petrovoltaics ... Earth Batteries ... John HUTCHISON / Hutchison Effect &c...


Classification: - international: H01M6/06; H01M6/16; H01M10/02; H01M6/04; H01M6/16; H01M10/02; (IPC1-7): H01M6/06; H01M6/16; H01M10/02

Abstract -- PURPOSE:To provide a semipermanent battery by putting far infrared radiation ceramic powder or a far infrared radiation ceramic powder pack in an inside electrolyte solution of a primary battery or a secondary battery, and naturally charging to recover the original potential. CONSTITUTION:Pulverized tourmaline fine powder belongs to far infrared radiation ceramics, and is put in an electrolyte of a battery as powder or being packed. It was found that even if the battery is discharged, the potential does not change. When a lithium battery was tested in the condition of 500mA discharge for 10 minutes and rest for 4 hours, voltage did not vary over 7 month. It is thought that the recess of an ionic crystal of the powder is charged positively and the other end is charged negatively to produce potential, dynamic energy such as temperature is converted into electric energy, and in addition by electromagnetic radiation from the far infrared radiation stone, oxidized electrolyte is reduced.



Classification: - international: D01F1/10; D01F2/06; D06M11/00; D06M11/49; D06M101/00; D06M101/02; D06M101/06; D01F1/10; D01F2/00; D06M11/00; (IPC1-7): D01F1/10; D01F2/06; D06M11/49
Also published as: JP2715034       

Abstract -- PURPOSE:To provide a permanent electrode fiber composed of a regenerated or synthetic fiber containing a tourmaline powder finely pulverized by a tromill in combination with a highly orientated crystalline tourmaline as a permanent electrode substance distributed in the fiber surface layer and capable of giving a favorable electric stimulation to the human body so as to activate the human body and to provide its production method. CONSTITUTION:A permanent electrode fiber containing a permanent electrode substance highly orientated and distributed in the surface layer of the fiber is formed by mixing the permanent electrode substance having electrodes at both the ends of the crystal structure in a regenerated or synthetic fiber.; The permanent electrode fiber containing a permanent electrode substance highly orientated and distributed in the surface layer of the fiber can formed also by uniformyl mixing and dispersing 1 to 5wt.% natural or artificial permanent electrode substance powdered into <=1mum liquefied raw material such as a regenerated or synthetic fiber or blending a suspension of a titanium oxide- containing permanent electrode substance powder with liquefied raw material such as a regenerated or synthetic fiber and spinning it through a spinning nozzle while allowing it to pass through an external magnetic field.

Artificially-synthesized tourmaline crystalline substance and its preparation method  


Inventor(s):     CHEN YANDONG [CN]
Classification: - international: C01B33/20; C01B33/00

Abstract -- The invention discloses an artificial synthetic tourmaline crystal and synthetic method, which consists 2-10 percent tourmaline and 90-98 percent mineral, wherein the tourmaline and mineral are grinded into grain size mixture less than 15 nm, which is grinded into grain size more than 15 nm after melted at more than 1600 deg.c. The invention can produce large amount of negative ion, which absorbs artificial synthetic tourmaline crystal with positive charge odor, bacteria, smog and harmful gas.

Dynamoelectric monomers, and self-discipline generating set of possessing the monomers  


Classification: - international: H01M10/36; H02J7/00; H01M10/36; H02J7/00

Abstract -- Pressing powder of tourmaline covered by lithium metal produces the disclosed power generation unit. The invention also discloses self-discipline generating set composed of multiple connected power generation units, as well as not contact charging circuit system including combinations between power generation unit and electromagnetism, or the unit and light, or the unit and solar energy. When accomplishing charging to self, the power generation unit can transport redundant electric energy to other power generation units at a time. The invention also includes micro intelligent operation system CPU in use for controlling and managing generating, charging electricity and transporting electricity to other units. In condition of without external electrical source, the disclosed power generation unit self can produce stable and long lasting electric energy.

Tourmaline nano metal oxide and preparation method thereof  


Inventor(s):     LI XUECHENG DING [CN]
Classification: - international: C01G1/02; C01G1/02

Abstract -- The invention relates to a nano tourmaline metal oxide, which especially can increase anion release efficiency. Said metal oxide comprises tourmaline metal oxide with grain size being 5-30nm and nano silver granular with grain size being 0.2-1 um; nano silver granular is attached to the surface of tourmaline metal oxide. The invention makes use of the tourmaline metal oxide coated with nano silver granular and the powder phase of tourmaline metal oxide to dramatically increase the release amount of anion and far infrared rays, which improves treating effect for human body. The invention aslo relates to the method for preparing said nano tourmaline metal oxide.



Classification: - international: E04B1/92; H05K9/00; E04B1/92; H05K9/00; (IPC1-7): H05K9/00; E04B1/92

Abstract -- PROBLEM TO BE SOLVED: To provide an electromagnetic wave disturbance preventing material which keeps an residence environment and an office environment free from an electromagnetic wave disturbance by using this material as an internal material in an office and a residence or external materials for various kinds of electric products and electronic appliances. ; SOLUTION: The material is composed of an electromagnetic wave absorbing and extinguishing member 1 formed by coating an unwoven fabric, paper, etc. with an electromagnetic wave absorbing and extinguishing substance formed by mixing the fine powder of tourmaline and that of bamboo charcoal into a binding material by adhesion, a decoration panel member 2 which is secured to one surface of the electromagnetic wave absorbing and extinguishing member, and composed of paper, cloth, an wood plate, a synthetic resin plate, a synthetic resin sheet, etc.; an electromagnetic wave reflection member 3 which is secured to the other surface of the electromagnetic wave absorbing and extinguishing member, and composed of a metal plate such as an aluminum plate and a stainless plate.

Device for Saving Electrical Power

WO 2008/133438

Inventor: CHOI, Sung

Abstract -- A device for saving electric power of the present invnetion comprises a case; a tourmaline insert accomodated in the case body, which is a mixture of tourmaline powder, permanent magnet powder and moisture (H2O); ionization paltes respectively positioned on the upper and lower surfaces of the tourmaline intermediate layer interposed therebetween and a conductive plate embedded in the termaline intermediate layer.

WO 2008/156489

Wireless Electrical Charging System

Abstract -- An apapratus wirelessly recharges a recahrgeable battery. The apparatus includes a wireless receiver that anmplifies radio waves, the wireless receiveer comprising a tourmaline and zeolite ceramic. The recharging apparatus also includes a patch antenna that filters the received radio waves to usable RF signals. The rechargin apparatus further includes circuits that process the usable RF signals to create refined electric power for the rechargeable battery.



Classification: - international: C02F1/42; C02F1/60; C02F1/68; C02F1/42; C02F1/60; C02F1/68; (IPC1-7): C02F1/60; C02F1/42; C02F1/68

Abstract -- PROBLEM TO BE SOLVED: To provide a method for easily removing silicon contained in water in a short time without using electric power and an equipment for the same. ; SOLUTION: A water excluding hard water containing silicon is allowed to pass through a container 12 housing obsidian 10 to add active hydrogen to the water. Thereafter, the water which has passed through the above container 12 is allowed to pass through an aluminum cartridge 28 housing tourmaline 32 and a metal 34 therein. Thereby, the silicon contained in the water is separated from the water through adhesion to the inner wall of the aluminum cartridge 28.



Classification: - international: A01C1/06; A01C1/00; A01C1/06; A01C1/00; (IPC1-7): A01C1/06; A01C1/00

Abstract -- PROBLEM TO BE SOLVED: To provide a coated seed having an excellent germination performance. ; SOLUTION: This coated seed is characterized in that the coating contains one or more kinds of ore powder radiating far IR light, such as tourmaline ore powder. Such the functional mineral radiates growing far IR light having wavelengths of 4 to 14[mu]m, and thereby promotes the germination of the seed. Many natural minerals contained in the ore promote the growth of crops and reinforce the disease resistance of the crops. The tourmaline ore is a porous ore, and has an electric characteristic that continuously flows a weak electric current. Therefore, the weak electric current stimulates the hair roots of plants to promote their growth. Since containing boron, the tourmaline ore can promote the absorption of water from the hair roots to prevent the fertilizer scorch of the hair roots. Therefore, the coated seed having a high germination rate and an excellent germination performance is obtained.

Tourmaline: Animal and Plant Growth promotion composition


Inventor: LEE HAE WANG
Classification: - international: A23K1/16; A23K1/175; A23K1/16; A23K1/175; (IPC1-7): A23K1/16; A23K1/175

Abstract -- A composition for promoting animals and plants containing tourmaline, loess, a loess solution(jijangsu), kaoline and other minerals is provided. It promotes the growth of plants while preventing disease and insect pest of the plants. It also promotes the growth of animals and fishes when fed thereto. CONSTITUTION: The animal and plant growth promoting composition contains tourmaline, loess, a loess solution (jijangsu), kaoline and minerals. The tourmaline is prepared by agitating tourmaline in a solution containing sulfuric acid, nitric acid and oxalic acid, washing and drying in a natural state or at 100deg.C or less. The kaolin is prepared by heating kaolin for 20min at 400 to 500deg.C and grinding to 100 to 325 meshes. The loess solution is prepared by heating loess at 200 to 300deg.C, grinding to 150 to 325 meshes, mixing with purified water in a ratio of 1:20 and then agitating.



Inventor(s):     PARK O KYU
Classification: - international: C02F9/12; C02F9/08; (IPC1-7): C02F9/12

Abstract -- PURPOSE: To provide a biological activation device for promoting activation of microorganisms in a sewage and wastewater treatment plant to improve treatment efficiency of sewage and wastewater and completely adsorb and remove odorous gas in exhaust gas generated from sewage and wastewater containing high concentrated organic matter and high concentrated nitrogen and phosphorus at the same time.  CONSTITUTION: The biological activation device for sewage and wastewater treatment plant comprises a sprinkling pipe(11) into which water to be treated flows; an activation illite ceramic layer(13) which is formed of a special ceramic so that the activation illite ceramic layer emits wavelength of far-infrared rays to generate energy and completely adsorb thus deodorize noxious gas by revolving electrons around the cell when a cell of microorganisms are divided; a permanent magnet layer(14) for generating magnetic force; an activation tourmaline ceramic layer(15) to which a weak electric current is consistently impressed by a magnetic field generated from the permanent magnet so that the activation tourmaline ceramic layer generates anions as a polar crystal that is formed of a special ceramic to have electric polarization itself; a crystalline graphite layer(16) installed on a lower part of the activation tourmaline ceramic layer; and a diffuser(18) into which exhaust gas generated from sewage and wastewater flows.

Method of controlling the growth of microorganism in a liquid with tourmaline crystals  


Inventor(s): KUBO TETSUJIRO [JP]
Classification: - international: C02F1/461; C02F1/48; C02F1/50; C02F1/467; C02F1/461; C02F1/48; C02F1/50; (IPC1-7): C02F1/68 - European: C02F1/461B4; C02F1/48; C02F1/50B

Abstract -- A method of electrodepositing removal of ionic material using tourmaline crystal and tourmaline crystal with electrodeposited metal according to the present invention utilize electrodepositing phenomenon whereby to the cathode (negative pole) of tourmaline permanent electrodes, the metallic ion which is anode ion having electric charge of the opposite character thereto is attracted, neutralized, and deposited as a metallic atom to form a metallic coating on the electrode surface. Hereinafter a method of electrodepositing removal of ionic material using tourmaline crystal and the specific structure of tourmaline crystal with electrodeposited metal according to the present invention will be described in detail.



Inventor(s):     GIOVANNINI ENORE [IT]
Applicant(s):     GIOVANNINI ENORE [IT]
Classification: - international: A61N1/20; A61N1/24; A61N1/34; A61N1/20; A61N1/32; (IPC1-7): A61N1/34; A61N1/20; A61N1/24 - European:     A61N1/20P; A61N1/24; A61N1/34
Also published as: ITBO20000391  (A1)      EP1299150  (A1) AU6935201  (A)     

-- A rebalancing device for the electric potential of the cell membrane includes a base support (2), constituted by a epoxy resin including isocyanate and toluol, associated with a piezoelectric mineral composition (3) fit for emitting electromagnetic fields at very low frequency. The piezoelectric mineral composition (3) is constituted essentially by 10-30 % of albite, preferably 15 %, 20-40 % of tourmaline, preferably 30 %, 10-50 % of quartz, preferably 30 %, 10-20 % of chlorite, preferably 13 % and 10-20 % of illite, preferably 12 %.



Classification: - international: A01G7/00; A01C1/00; A01C1/08; A01G16/00; A01G7/00; A01C1/00; A01G16/00; (IPC1-7): A01G7/00; A01C1/00; A01C1/08; A01G7/00; A01G16/00

Abstract -- PROBLEM TO BE SOLVED: To make ready to control a time for germination and blooming. SOLUTION: This method for cultivation uses controllers for a high-frequency alternating current low voltage and a high-frequency alternating current high voltage and electrode plates connecting to the controllers. The objective cultivation is performed by using reduced water obtained from the devices or mixing the water with an ore containing various mineral components, an electric stone such as tourmaline or various organic mineral, or using lactic acid bacterium bioactive substance, water-soluble chitosan, a high electroconductive activated carbon, an organic fertilizer and manure or an effective microorganism such as actinomycetes, according to the object, utilizing titanium oxide, ceramic using transition element or an ultraviolet light, and further using pyroligenous acid or a spreader or using an extracted solution from Japanese andromeda, Arisaema serratum or a garlic. The objective method is performed by using a water storage tank, utilizing a water-supplying pump or a water discharging pump, using hydroponic equipment of facility of a vinyl house, applying a sprayer or applying sterilized water, according to the culturing method.

Acta Cryst. (1977). A33, Part 6 (November 1977), 927-932    [ doi:10.1107/S0567739477002241 ]

Structural mechanism of pyroelectricity in tourmaline

G. Donnay

Abstract: Pyroelectricity in tourmaline, known since antiquity, was ascribed by S. von Boguslawski to a charged, asymmetric, anharmonic oscillator based on the Einstein model of a crystal. His predicted values of the pyroelectric coefficient k were in good agreement with Ackermann's measurements in the range 20-400 K. We have tested Boguslawski's model by refining the structure, at 193 and 293 K, on a sphere of gem-quality elbaite. The pyroelectric effect is due primarily to the asymmetric anharmonic vibrations of O(1), the oxygen atom of point symmetry 3m which has a polar environment. Its centre of gravity moves 0.005 Ĺ from 193 to 293 K. It is the only atom with a displacement well above experimental uncertainty. Its large thermal parameters, which are ten times their standard deviation at both temperatures, clearly invalidate the assumption of an ellipsoidal thermal movement. This probably holds for Na and 0(2), which also have abnormally large temperature factors, but show no significant displacement. 

World Journal of Microbiology and Biotechnology -- Volume 24, Number 5 / May, 2008, Pages    725-731
DOI    10.1007/s11274-007-9529-x

Tourmaline ceramic balls stimulate growth and metabolism of three fermentation microorganisms

He Ni, Ling Li and Hai-Hang Li

(1) Guangdong Provincial Key Lab of Biotechnology for Plant Development and College of Life Sciences, South China Normal University, Guangzhou, 510631, China

Abstract -- Effects of tourmaline ceramic balls on growth and metabolism of Saccharomyces cerevisiae, Lactobacillus acidophilus and Aspergillus oryzae were studied. Treatments with 3, 6, 9 or 12 g of tourmaline ceramic balls in a 50 ml culture showed significant stimulation of the growth of the three microorganisms. In optimal treatments with 12 g of tourmaline balls, the growth of S. cerevisiae, L. acidophilus, and A. oryzae was increased by 34, 32 and 10%, respectively. After 72 h fermentation of S. cerevisiae, total carbohydrate content in the culture medium was decreased by 65% and ethanol production was increased by 150%. Total carbohydrate content was decreased by 80% and the pH value was decreased by 0.3, as a result of organic acid production in the medium of L. acidophilus after 72 h fermentation. In the case of A. oryzae, enzyme activities of protease and amylase were increased by 90 and 31%, respectively, after 96 h fermentation. Results indicated that tourmaline stimulates initiation of growth in the early lag stage and increases production of metabolites at a later stage of fermentation. The strong stimulatory effect of tourmaline on growth, utilization of substrates and production of metabolites in the three microorganisms suggests a potential application in the fermentation industry.

Contact Information     Hai-Hang Li

Tourmaline Composition, Crystallization & Structure

Composition. A complex silicate of boron and aluminum, containing varying amounts of ferrous iron, magnesium, manganese, calcium, sodium, potassium, lithium, hydroxyl and fluorine.

Crystallization. Hexagonal-rhombohedral; hemimorphic. Crystals usually prismatic, vertically striated. A triangular prism, with three faces, prominent, which with the tendency of the prism faces to be vertically striated and to round into each other gives the crystals usually a cross section like a sphericaltriangle. Crystals are commonly terminated by base and low positive and negative rhombohedrons; sometimes scalenohedrons are present When the crystals are doubly terminated they usually show different forms at the opposite ends of the vertical axis (homomorphism).

Structure. Usually in crystals. Sometimes massive compact; also coarse to fine columnar, either radiating or parallel.

Physical Properties. Vitreous to resinous luster. Color varied, depending upon the composition. Common tourmaline with much iron is black, sometimes brown. More rarely light colored in fine shades of red, pink, green, blue, yellow, etc. Rarely white or colorless. A single crystal may show several different colors either arranged in concentric bands about the center of the crystal or in transverse layers along its length. Strongly pyroelectric; i.e., when cooling from being heated to about 100° C. it develops positive electricity at one end of the crystal and negative at the other, which enables the crystal to attract and hold bits of paper, ete. Strongly diachronic; Le., light traversing the crystal in one direction may be of quite a different color or shade of color from that traversing the crystal in a direction at right angles to the first. H. = 7-7.5; G. = 2.98-3.2.

Tests. To be recognized usually by the characteristic rounded triangular cross section of the crystals; absence of prismatic cleavage, coal-like fracture of black variety.

Occurrence. Tourmalinc is one of the most common and characteristic minerals formed by pneumatolytic action. That is, it is a mineral that has been formed at high temperatures and pressures through the agency of vapors carrying boron, fluorine, ete. It is found, there fore, commonly as an accessory mineral in pegmatite veins, 01' dikes, occurring with granite intrusions. Associated with the ordinary minerals of granite pegmatite, orthoclase, albite, quartz and muscovite; also with lepidolite, beryl, apatite, fluorite, ete.

Found also as an accessory mineral in metamorphie roeks, such as gneisses, schists and crystalline limestones.

The black tourmaline is of widespread occurrence as an accessory mineral in metamorphie rock. The light colored gem varieties are found in the pegmatite dikes. Famous localities for the occurrence of the gem tourmalines are the island of Elba; in the state of Minas Geraes, Brazil; Ural Mountains near Ekaterinburg; Madagasear; Paris and Auburn, Maine Chesterfield, Massachusetts; Haddam Neck, Connecticut; Mesa Grande, Pala, Rincon and Ramona in San Diego County, California. Brown crystals are found near Gouverneur, New York and fine black crystals at Pierrepont, New York.

Physical properties of tourmaline


Darrell Henry

Campanile Charities Professor of Geology and Geophysics at Louisiana State University -- research specialty : metamorphic petrology.

Contact -- (225)-578-2693, fax (225)-578-2302 or e-mail .
Address: Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803.


Bhaskara-Rao, A. and de Assis, A. D. (1968) Chatoyant and pseudomorphosed tourmalines in northeastern Brazil. Journal da Mineralogia (Brazil), 6, 31-36.

Eppler, W. F. (1958) Notes on asterism in spinel and chatoyancy in chrysoberyl, quartz, tourmaline, zircon and scapolite. Journal of Geramology, 6, 251.

Graziani, G., Gubelin, C. G., and Lucchesi, S. (1982) Tourmaline chatoyancy. Journal of Gemmology, 18, 181-193.


Elastic constants

Helme, B. G. and King, P. J. (1978) The elastic constants of iron tourmaline (schorl). Journal of Materials Science, 13, 1487-1489.

Huntington, H. B. (1958) The elastic constants of crustals. Solid State Physics, 7, 213-353.

Newaham, R. E. and Yoon, H. S. (1973) Elastic anisotropy in minerals. Mineralogical Magazine. 39, 78-84.

Ozkan, H. (1979) Elastic constants of tourmaline. Journal of Applied Physics, 50, 6006- 6007.

Tatli, A. (1985) Zero-field elastic constants of uvite. Journal of the Physics and Chemistry of Solids, 46, 1015-1018.

Tatli, A. and Ozkan, H. (1987) Variation of the elastic constants of tourmaline with chemical composition. Physics and Chemistry of Minerals, 14, 172-176.

Electrical properties

Arons, A. B., Cole, R. H., Kennedy, W. D. and Wilson, E. B. Jr. (1947) Design and use of tourmaline gages for piezoelectric measurement of explosion phenomena. Physical Reviews, 72, 176-177.

Baird, G. A. and Kennan, P. S. (1985) Electrical response of tourmaline rocks to a pressure impulse. Tectonophysics, 111, 147-154.

Barker, B. (1980) Aschentrekker. Gems and Gemology, 16, 375-378.

Bergmann, T. 0. (1766) Commentarius de indole Electrica Turmalini. Philosophical Transactions of the Royal Society of London, 56, 236-243.

Butler, Edward Taylor (1962) Methods of determining pyroelectricity in tourmaline. American University, United-States; Master's 40 p.

Curie, J. and Curie, P. (1880) Developpment par compession de lelectricite polaire dans les cristaux hemiedres a faces inclinees. Bulletin de la Societe Mineralogie de France, 3, 90.

Donnay, G. (1977) Structural mechanism of pyroelectricity in tourmaline. Acta Crystallographica, A, 33, 927-932.

Drozhdin, S. N., Novik, V. K., Koptslk, V. A. and Kobyakov, I. B. (1975) Pyroelectric properties of tourmaline and cancrinite crystals in a wide range of temperatures. Soviet Physics, Solid State. 16, 2122-2123.

Frondel, C. (1948) Tourmaline pressure gauges. American Mineralogist, 33, 1-17.

Gaugain, J. -M. (1856) Note sur les proprietes Electriques de Ta tourmaline. Comptes Rendus Hebdomadaires des Seances de l’Academie des Sciences (Paris). 42, 1264-.

Gaugain, J. -M. (1859) Memoire sur lelectricite des tourmalines. Annales de Chimie et de Physique. 57, 5-11.

Gavrilova, N. D. (1965) Study of the temperature dependence of pyroelectric coefficients by the static method. Kristallografiya, 10,278-281.

Gavrilova, N. D., Drozhdin, S. N., Novik, V. K. and Maksimov, E.G. (1983) Relationship between the pyroelectric coefficient and the lattice dynamics of the pyroelectrics. Solid State Communications, 48, 129-133.

Gladkii, V. V. and Zheludev, I.S. (1956) Methods and results of an investigation of the pyroelectric properties of some single crystals. Kristallografiya, 10, 63-67.

Hamid, S. A. (1980) Tourmaline as a pyroelectric infra-red radiation detector. Zeitshrift fur Kristallographie, 151, 67-75.

Hauy, R. J. (1785) Memorie sur les proprietes electriques plusieurs mineraux. Memoires de l'Academie Royale des Sciences, 206.

Hawkins, K. D., Mackinnon, I. D. R. and Schneeberger, H. (1995) Influence of chemistry on the pyroelectric effect in tourmaline. American Mineralogist, 80, 491-501.

Hearst, J. R., kani, G. B., and Geesaman, L. B. (1965) Piezoelectric response of Z-cut tourmaline to shocks of up to 21 Kilobars. Journal of Applied Physics, 36, 3440-3444.

Helme, B. G.M. and King, P. J. (1977) Microwave acoustic relaxation absorption in iron tourmaline. Journal de Physique (Paris) 38, 1535-1540.

Home, R. W. (1976) Aepinus, the tourmaline crystal, and the theory of electricity and magnetism. Isis, 67, 21-30.

Keys, D. A. (1921) A piezoelectric method of measuring explosion pressures. Philosophical Magazine (London, Edinburgh, and Dublin), 42, 473-488.

Keys, D. A. (1923) The adiabatic and isothermal piezo-electric constants of tourmaline. Philosophical Magazine, 46, 999-1001.

Kittinger, E., Seil, and Tichy, J. (1979) Electroelastic effect in tourmaline. Zeitschrift fur Naturforsh., 34a, 1352-1354.

Lastovickova, M. and Povondra, P. (1988) High temperature electrical conductivity of tourmalines. Zhdanov, M. S., Berdichevsky, M. N., Fainberg,

Lewis, M. F., and Patterson, E. (1972) Assessment of tourmaline as an acoustic-surface- wave-delay medium. Applied Physics Letters, 20, 275-276.

Lewis, M. F., and Patterson, E. (1973) Microwave ultrasonic attenuation in topas, beryl, and tourmaline. Journal of Applied Physics, 44, 10-13.

Martin, A. J. P. (1931) On a new method for detecting pyroelectricity. Mineralogical Magazine 22,519-523. Mason, W. P. (1950) Piezoelectric Crystals and their Application to Ultrasonics. Van Nostrand, New York.

Maurice, M. E. (1930) On the demonstration of electric lines of force and a new method of measuring the electric moment of tourmaline. Cambridge Philosophical Society Proceedings. 26, 491-495.

Maxwell, J. C. (1873) A Treatise on Electricity and Magnetism. Oxford Press, Clarendon, England.

Mishra, S., Krishna Rao, A. V. and Rao, K. V. (1989) Dielectric properties of tourmaline under different conditions. Pays. Stat. Solidi A – Applied Research, 114, K115-K118.

Nambi, K. S. V. (1984) Pyroelectroluminescence induced by tourmaline. Physica Status Solidi A – Applied Research. 82, K71- .
Niwa, Y., lizawa, O., Ishimoto, K., Jiang, X.X. and Kanoh, T. (1993) Electromagnetic-wave emitting products and Kikoh potentiate human-leukocyte flinctions. International Journal of Biometeorology, 37, 133-138.

Peng, M. S. and Wang, H. Y. (1994) Research on relation of tunnel structure to electrical properties of tourmaline. International Mineralogical Association Meeting Abstracts, 16, 321.

Rao, D. A. A. S. N. (1949) Dielectric constants of crystals, III. Indian Academy of Science Proceedings, 30A, 82-86.

Rao, D. A. A. S. N. (1950) Dielectric constants and elastic moduli of uniaxial crystals. Current Science (India) 19, 116.

Rozhkova, E. V. and Proskurovskii, L. V. (1957) Dielectric permeability determination on minerals and their dielectric separation. Sovremennye Metody Mineralogicheskogo Issledovaniya Gornykh Porod. Rud i Mineralov, pp.115-138.

E. B., Spichak, V. V. Ninth workshop on Electromagnetic induction in the Earth and Moon. Abstracts Workshop on Electromagnetic Induction in the Earth and Moon. 9. p.101

Waesche, H. H. (1949) Importance and application of piezoelectric minerals. Mining and Engineering, 1, 12-16.

Yamaguchi, S. (1964a) Electron diffraction of a pyroelectric tourmaline crystal. Journal of Applied Physics, 35, 1654-1655.

Yamaguchi, S. (1964b) Electron diffraction of a pyroelectric tourmaline crystal. Naturwissenschaften, 51, 55.

Yamaguchi, S. (1983) Surface electric fields of tourmaline. Applied Physics, A-31, 183-185.


Kirby, S. H., Hemingway, B. S. and Lee, R. W. (1990) Anomalous fracture and thermal behavior of hydrous minerals. in Duba, A. G., Durham, W. B., Handin, J. W. and Wang, H. F. The Brittle-ductile transition in rocks. Geophysical Monograph, 56, 119-126.


Ivanova, T. N. (1981) Microhardness of minerals of the tourmaline group. Diagnostika i Diagnosticheskie Svoistva Mineralov Proceedings, pp.237-239. (Russian)


Calderon, T. (1987) Factores que afectan in termolurninescencia en turmalinas: Elbaita. Boletin de Ia Sociedad Espanola de Mineralogia, 10, 191-197

Calderon Garcia, T. and Coy-Yll, R. (1982) Thermoluminescence in elbaite. Journal of Gemmology, 18, 217-221.

Jain, V. K. and Mitra, 5. (1977) Thermoluminescence studies on some silicate minerals. Thermochimiac Acta, 18, 241-244.


de Camargo, W. G. R. and Souza, I. M. (1970) Novo Habito da Turmalina. Academia Brasileira de Ciencais Anais (Rio de Janeiro), 42, 219-222.

Gaines, R. V. and Thadeu, D. (1971) The minerals of Panasqueira, Portugal. Mineralogical Record, 2, 73-78.

Heinrich, E. W. (1963) Notes on western mineral occurrences. American Mineralogist, 48, 1172-1174.

Kuz'min V. I., Solntseva L. S., Konev A. S. (1976) Tipomorfnye osobennosti turmalina. Translated title: typomorphic features of tourmaline. In Novoe v mineralogicheskih issledovanijah. M., p. 41-43 (in Russian).

Rowley, E. B. (1942) Huge tourmaline crystals discovered. Mineralogist, 10,47-48, 63-64.

Rub, A. K. (1973) Silicates. Typomorphism of topaz and tourmaline, characteristic accessory minerals of tantalum and tin ore mmeralizations (as illustrated by a region in the eastern U.S.S.R.). Tipomorphism Mineralov i Ego Prakticheskoe Znachenie, pp.178-185.

Solly, R. H. (1884) On the tetartohedral development of crystal of tourmaline, Mineralogical Magazine, 6, 80-82.

Termier, P. (1907) Large tourmaline crystals from Ankaratra. Bulletin de la Societe Fraucaise de Mineralogie, 31, 138-142.

Williams, E. H., Jr. (1876) On crystals of tourmaline with enveloped orthoclase. American Journal of Science, 11, 274-275.

Wooster, W. A. (1976) Etch figures and crystal structures. Kristall und Technik, 11, 615-623.

Surface properties

Houchin, M. R. (1986) Surface studies of aqueous suspensions of tourmaline (Dravite). Colloids and Surfaces, 19, 67-82.

Nakamura, T. and Kubo, T. (1992) Tourmaline group crystals reaction with water. Ferroelectrics, 137,1-4.

Nishi, Y., Yazawa, A., Oguri, K., Kanazaki, F. and Kaneko, T. (1996) pH self-controlling induced by tourmaline. Journal of Intelligent Material Systems and Structures, 7, 260-263.

Yamaguchi, S. (1983) Tourmaline as a gas-chromatographic sensor. Materials Chemistry and Physics, 8, 493-498.

Thermal properties

Horai, K. (1971) Thermal conductivity of rock forming minerals. Journal of Geophysical Research, 76, 1278-1308.

Kurylenko, C. (1950) Analyse thermique de quelques tourmalines. Bulletin de la Societe Francaise de Mineralogie et de Cristallographie, 73, 49-54.

Lawless, W. N. and Pandey, R. K. (1984) Glasslike thermal conductivity of tourmaline at low temperatures. Solid State Communications, 52, 833-835.

Darrell Henry is the Campanile Charities Professor of Geology and Geophysics at Louisiana State University whose research specialty is metamorphic petrology. Further details of his professional background are included in an accompanying vita or faculty profile.

To contact Darrell Henry call (225)-578-2693, fax (225)-578-2302 or e-mail . Address: Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803.