Physical Properties:
Moh's Scale Hardness: 8.5
Specific Gravity: 3.68 - 3.75
Refractive Index: 1.745 - 1.759
Fracture: conchoidal, brittle
Crystal Habit: prismatic crystals are elongated on c axis.
Colors: green in daylight and red-violet in incandescent light.

General Information:
Alexandrite is the rare and unique color-change variety of chrysoberyl. It is the birthstone for the month of June. Alexandrite was first discovered in 1830 in Russia, on the first day that the Russian Czar Alexander II came of age. For this, the founder named the gemstone after the Czar. Alexandrite is known for its unique characteristics to change color from green to red. This color change gave us the description “emerald by day, ruby by night.”  To see the color change in an alexandrite, look at the stone under incandescent lighting, and daylight.
Lab Created Alexandrite CorundumAlexandrite with more color change is considerably more valuable, some gems will change 100% and others as little as 5% of a change can be seen. In daylight alexandrite hues range from very strongly bluish green through yellowish green and in incandescent lighting they are orangy red through purple-red.


Russia has long been the most known and desirable source for Alexandrite. The Russian mountains produce little today. It has also been found in Brazil, but these alexandrite mines are currently under control by the government. Alexandrite found in Sri Lanka usually has very low color change, often times being able to be seen under laboratory conditions only.


Common Treatments and Lab Created Forms: Lab Created Alexandrite Chrysoberyl
There is no treatment done on alexandrite.
There are several alternatives to the expensive natural alexandrite gemstone. Lab created chrysoberyl has been created and is on the market for significantly less than the natural gem. This lab chrysoberyl has the same properties and is identical in composition to the natural alexandrite. All other options for this gemstone are simulants and are not a true alexandrite even though they may have similar physical properties. Lab alexandrite corundum is a popular option, which is lab created sapphire that has a color change similar to that of natural alexandrite. There are also cubic zirconia that change color, and colored glass available.