Above: Front of the Specimen Card
Formed in volcanic rocks and colored violet by radiation, amethyst has an explosive origin. The traditional birthstone of February, it can be found around the world and is sought after for its beautiful purple hues.
Above: Polished Amethyst Specimens
An amethyst’s coloring is due to impurities in its crystal structure. The gemstone is made up primarily of quartz, a silicate that is normally a clear and colorless mineral. In some cases though, trivalent iron may be substituted for silicon. Radiation affecting the mineral helps this substitution and the internal lattice then becomes warped, causing it to refract light in such a way that the gem appears purple. Different intensities of impurities can cause amethyst to appear in different shades, from deep purples to light lavender. Colors vary from gem to gem and can be different within individual amethysts.
Above: Macro image of Amethyst Specimens displaying the variety and richness of color.
This specimen is a single polished amethyst crystal from Rio Grande do Sul in Brazil. The specimen is housed in an acrylic jar that is encased within a glass-topped riker display box. The box measures 4 1/2" x 3 1/2". A small information card is also included, which serves as the certificate of authenticity.
More About Amethysts
"To Dionysos alone had Rheia given the amethyst, which preserves the wine drinker from the tyranny of madness." ~ The Dionysiaca
Above: Macro image of a raw amethyst crystal measuring roughly 1" in diameter. This crystal was immersed in water before taking the picture, which is one way to bring out the shine in these gemstones.
Crystals of amethyst can form in many different shapes. Some grow from the cavities of other rocks in a geode structure, others appear as scepters, split-growth crystals, and occasionally amethyst deposits can even fill in tunnels from hydrothermal vents. These veins grow at different rates over time, causing variation in the color and shape of the crystals, with dark and light stripes of purple appearing right beside each other.
Amethyst gets its name from the Greek prefix "a-", which means not, and "methysko" which means intoxicate. This is due to the ancient belief that the stone could allow one to drink wine without getting drunk. In Nonnus’ Dionysiaca, the Greek god of wine, Dionysus is gifted the gem in order to prevent him from going mad. Cups and glasses that were carved from amethyst were thought to impart this resistance onto the drinker and many have been found dating back to antiquity.
One of the most abundant sources of amethyst are the volcanic geodes of Rio Grande do Sul in Brazil. Hidden underneath these basaltic flows lay a massive amount of amethyst deposits, with some deposits having metric tons of material. Geodes in this region can be massive, with some being over 9 feet long.
Above: Amethyst mining Rio Grande do Sul is a hands-on process.
Artifacts made from amethyst can be found throughout history and around the world, with beads and jewelry appearing in ancient Egypt, Greece, the pre-colonial Americas, medieval Europe, and India. The beauty of these stones has always captured the eye of humans. Today, amethyst is cut and polished in order to be used for all kinds of jewelry.
Lameiras, Fernando, et al. "Infrared and chemical characterization of natural amethysts and prasiolites colored by irradiation." Mat. Res., vol. 12, no. 3, July/Sept. 2009.
"Esoteric Materials: Amber, Amethyst, Gold and Silver." The Early Anglo-Saxon Kingdoms of Southern Britain AD 450-650: Beneath the Tribal Hidage, by Sue Harrington and Martin Welch, Oxbow Books, Oxford; Philadelphia, 2014, pp. 155–173.
Cohen, Alvin J., and Farkhonda Hassan. "Iron in Synthetic Quartz: Heat and Radiation Induced Changes." Science, vol. 167, no. 3915, 1970, pp. 176–177.
De Brito Barreto, Sandra, and Sheila Maria Bretas Bittar. "The Gemstone Deposits of Brazil: Occurrences, Production and Economic Impact." Boletín De La Sociedad Geológica Mexicana, vol. 62, no. 1, 2010, pp. 123–140.
Above: Back of the Specimen Card