Alexandrite
Alexandrite is a truly rare gem, much rarer than diamonds of comparable quality. Almost unavailable except for estate jewelry just a few dozen years ago, this gem is now being produced in Brazil, East Africa, Russia, India and Sri Lanka. Alexandrite was supposedly discovered on the birthday of Alexander II, Czar of Russia, in 1830. It is unusual because it changes from purplish-red under candlelight or house lights, to green in daylight. The actual amount of color change varies from stone to stone and has a major impact on the stone's value. Alexandrite, the birthstone for June, is an untreated, natural gemstone. It has a hardness of 8.5 which makes it a good choice for all types of jewelry.
Treatments: none (many synthetics however)