Amethyst - the Birthstone of February

Amethyst is crystalline quartz in colors ranging from pale lilac to deep reddish purple. With a relatively high hardness of 7, the February birthstone is a fine facetable jewelry gem for all purposes and many of those can be found on SilverAndGold.com or while watching SNG TV. Lower grades of material can be cabbed, carved, and made into a great variety of beads and other ornamental objects. Value for amethysts depends almost entirely on color.

 Amethyst Crystal

Siberian mines once produced the world’s finest stones. They featured a particularly rich purple color that glowed with red and blue flashes. Today the term “Siberian” no longer refers to origins. Instead, this is now a trade and grade term referring to colors similar to those of the amethysts mined in Siberia. SilverAndGold.com offers a great deal of Siberian Amethyst along with specialized styles from other parts of the world.

Although Siberian reigns atop the value listing, light-colored amethyst has enjoyed a resurgence in popularity. The lightest, pinkish violet shades are called “Rose de France,” a clever bit of marketing. The artistry of gemstone faceting can shine through these gems if given fancy and unusual cuts. While rare, Amethyst stones can also be carved and a variety of Amethyst stone carvings can be found on SilverAndGold.com.

Amethyst Earrings

Since amethyst is readily available in large sizes, its value per carat climbs gradually. Since this stone is plentiful, there is little reason to pay top dollar for pieces with visible inclusions or inferior cutting.

STATISTICAL DATA FOR AMETHYST

Name Amethyst
Is a Variety of Quartz
Crystallography Hexagonal (Trigonal)
Refractive Index 1.544–1.553
Colors Pale lilac to deep reddish purple. May have color zoning.
Luster Vitreous
Polish Luster Vitreous
Fracture Luster Vitreous
Hardness 7
Wearability Very Good
Fracture Conchoidal to uneven
Specific Gravity 2.651
Birefringence 0.009
Cleavage None or indistinct
Dispersion 0.013
Luminescence Inert to weak blue in SW. Inert in LW.
Luminescence Present Yes
Luminescence Type Fluorescent, UV-Short
Enhancements Amethyst can be heat treated to improve the color or change it to citrine. Not common.
Typical Treatments Heat Treatment
Transparency Transparent to translucent
Absorption Spectrum Weak band, 550-520
Birthstone February
Formula SiO2
Pleochroism Weak to moderate, purple and reddish purple.
Optics o = 1.544; e = 1.553 (very constant). Uniaxial (+)
Optic Sign Uniaxial +
Etymology From the Ancient Greek amethystos, meaning “not drunk.” It was believed you could drink all night and remain sober if you had an amethyst in your mouth.
Occurrence Generally in pegmatites and veins. Found in geodes in alluvial deposits.
Inclusions Prismatic crystals and negative cavities, thumbprint marks, so-called rippled fractures, and twinning lines.

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