The Magic and Science of Jewels and Stones

by Isidore Kozminsky

CHRYSOLITE—OLIVINE

• Crystalline System: Orthorhombic.
• Hardness: 6-7.
• Lustre: Vitreous. Transparent to translucent.
• Refraction: Double.
• Chemical Composition: Silicate of Magnesium and Iron.
• Chemical Symbol: (Mg,Fe)₂SiO₄.
• Specific Gravity: 3.3-3.5.
• Dichroism: Distinct.
• Properties: Friction induces electricity in the stone which is infusible before the blowpipe, but is affected, whitening and forming with Borax, a yellow bead. Decomposes in Hydrochloric acid.
• In the Zodiac: The Peridot is under the Heavenly Pisces.
• Where found: United States, Ireland, Australia, (Queensland particularly), etc. A large number of Meteorites contain Peridots.

QUARTZ

ROCK CRYSTAL, AMETHYST, CAIRNGORM, CHRYSOPRASE, CATSEYE, PLASMA, JASPER, CARNELIAN, AGATE, ONYX, SARDONYX, MOSS AGATE

• Crystalline System: Rhombohedral.
• Hardness: 7.
• Lustre: Vitreous. Splendent to dull and resinous.
• Refraction: Double.
• Chemical Composition: Silicon 46.67. Oxygen 53.33.
• Chemical Symbol: SiO₂.
• Specific Gravity: 2.5-2.8. In pure crystals 2.65.
• Dichroism: Distinct.
• Properties: Generates positive electricity by friction. It is infusible under the blowpipe, but effervesces with Carbonate of Soda. Although it resists the common acids it may be dissolved in Hydrofluoric.
• In the Zodiac: Rock Crystal is under the Heavenly Pisces; Amethyst is under the Heavenly Aries; Cairngorm under the Heavenly Scorpio; Chrysoprase under the Heavenly Cancer; Catseye under the Heavenly Capricorn; Plasma under the Heavenly Virgo; Jasper under the Heavenly Virgo; Bloodstone under the Heavenly Leo; Camelian under the Heavenly Leo; Agate under the Heavenly Scorpio; Onyx under the Heavenly Capricorn; Sardonyx under the Heavenly Leo; Moss Agate under the Heavenly Taurus.
• Where found: Distributed plentifully about the world. Rock Amethyst is found in the United States, Brazil, India, Ceylon, Ekaterinburg, Australia, etc. Mr. R. J. Dunn, late Victorian Geologist, discovered large quantities of Rose Quartz in South Africa. It is also found in the United States, Russia, Australia and other places. Catseyes are found in Ceylon and India. Cairngorm is found in Scotland, United States, Australia, etc. Chrysoprase is found in the United States and other places.

SPINEL

SPINEL RUBY, BALAS RUBY, RUBICELLE, PLEONASTE OR CEYLONITE

• Crystalline System: Isometric.
• Hardness: 8-8½.
• Lustre: Vitreous.
• Refraction: Single.
• Chemical Composition: Alumina 72. Magnesia 28.
• Chemical Symbol: MgAl₂O₄.
• Specific Gravity: 3.5-4.0.
• Dichroism: None.
• Properties: Does not display electricity when submitted to friction or heat, but under heat the red spinel changes to brown. On cooling it becomes green, after which it is nearly colourless; then it resumes its pristine hue. Spinel crystals also change into Hydrotalcite, a soft pearl-like stone of similar chemical composition. Infusible alone under the blowpipe but yields slowly with Borax. It is soluble in concentrated Sulphuric Acid.
• In the Zodiac: Spinel, Balas, Almandine, Ruby and Sapphirine are under the Heavenly Virgo. The Chloro-Spinel and the Pleonaste are under the Heavenly Capricorn.
• Where found: United States, Canada, Burma, Siam, Ceylon, Australia, etc. It is discovered in granular limestone, in gneiss and rocks of volcanic origin.

SPODUMENE

KUNZITE—HIDDENITE