Alexandrite and pearls are both the June birthstone. Alexandrite is a hard, durable gemstone that changes colors from green to red. Because of its rarity and unique color properties, this is an expensive stone that is in high demand.
History
Alexandrite was discovered in the emerald mines of Russia in 1831. The gemstone was named for Czar Alexander II, the leader of Russia at the time. The largest and rarest pieces of alexandrite have been discovered in Tokovaya, a small cluster of mines outside Ekaterinburg, Russia. Because of the green and red hues inside the gemstone, alexandrite became the national stone. It was also thought to give mystical powers, the possibility of predicting the future and providing the wearer with good health and luck.
Today, Russia is still the primary source for alexandrite, although stones are being unearthed in Brazil, Tanzania, Burma, Madagascar, and Zimbabwe. In the past decade, alexandrite has also been found in India. The largest cut piece of alexandrite is 66 carats and can be viewed at the Smithsonian.
In addition to naturally occurring alexandrite, synthetic alexandrite, stones created in a laboratory, are widely used in jewelry. Synthetic alexandrite is also found in lasers primarily utilized in hair and tattoo removal.
What is Alexandrite?
Alexandrite is part of the family of gemstones known as chrysoberyl. It’s a hard, durable stone rated at 8.5 on the Mohs Scale. The specific gravity of alexandrite is between 3.64 and 3.74. The specific gravity weighs the density of a stone in comparison to the volume of water displaced.
Alexandrite is one of three chrysoberyls, sharing mineral properties with a transparent chrysoberyl and chrysoberyl cat’s eye (also known as cymophane). Alexandrite is scarce because of the specific chemical composition that gives the gemstone its ability to change colors in different lights. In addition to iron and titanium, alexandrite is made of chromium. It is chromium and, possibly the element vanadium, which transforms alexandrite from a colorless transparent stone to one with color-changing properties.
Beryllium and chromium, two elements contained within chyrsoberyls, are usually found within contrasting rock types. At the same time, silica is not present where alexandrite is found. This is critical because silica is the second most common element in the Earth’s crust and is needed for the growth of emeralds. Without silica, alexandrite can grow where emeralds would usually be found.
Color Changing Properties
Alexandrite is also one of the few gems that can actually change colors depending on the time of day and amount of light hitting the gem.
Alexandrite often appears to be a rich green or bluish-green color when sunlight reflects off the stone. That same gemstone reflects red hues at night when seen under incandescent light (light bulbs or candles) turning from a light shade of red to a deep purplish-red. The color change is caused by aluminum impurities in the stone being displaced by chromium oxide. The color can also shift depending on your viewing angle, a phenomenon known as pleochroism. Alexandrite is not the only gemstone that can change colors, tourmalines and opals can also appear to be different colors based on the different elements within the stones.
Buying Alexandrite
Alexandrite is a popular choice for people looking to mark a variety of occasions, but its price and rarity have ensured a variety of options are available in the marketplace. A lot of the jewelry containing alexandrite are antiques or period pieces because of the gemstone’s scarcity. Natural stones might be polished or cut; but are typically untreated.
- Synthetic alexandrite is created in a lab and mirrors the appearance and chemical makeup of natural alexandrite. A simulant has the appearance, but not chemical properties of the stone.
- Pearls are typically the more affordable birthstone for June and are considered an acceptable alternative to alexandrite.
- Alexandrite is the stone associated with a 55th wedding anniversary.
- The color properties of alexandrite have even inspired a new brown red shade of lipstick from Chanel.
Related Alexandrite Resources
About.com Chemistry: Tourmaline [1] About.com Jewelry: Opals [2] About.com Geology: Gem Color Changes [3] About.com Jewelry: Alexandrite Discovery [4] About.com Jewelry: Chrysoberyl [5] About.com Jewelry: June Birthstone [6] About.com Jewelry: Mohs Scale [7] About.com Jewelry: Natural Stones [8] About.com Jewelry: Pearls [9] About.com Makeup: Chanel Lipstick [10] About.com Marriage: Wedding Anniversary Gemstones [11] Alexandrite Tsarstone Collectors Guide: Alexandrite Myths, Legends and Lore [12] Alexandrite Tsarstone Collectors Guide: Alexandrite Simulants [13] Alexandrite Tsarstone Collectors Guide: Chrysoberyl Chemical Composition [14] Alexandrite Tsarstone Collectors Guide: Three Kinds of Chrysoberyls [15] American Gem Trade Association: Alexandrite Period Pieces [16] Antique Jewelry University: Alexandrite [17] Beadage: Alexandrite Pricing [18] Emporia State Univerysity: 66 Carat Alexandrite Gem [19] Enchanted Learning Rocks and Minerals Dictionary: Alexandrite [20] Excaliber Mineral Company: Pleochroism in Minerals [21] Gemological Institute of America: Alexandrite Color Changes [22] Gemology: Alexandrite [23] International Colored Gemstone Association: Alexandrite [24] International Colored Gemstone Association: Alexandrite Laser [25] Mindat.org: Where Chrysoberyls Are Found [26] Palagems: Russian Alexandrite [27] Scribd: Alexandrite [28] Your Gemologist: Synthetic Alexandrite [29]