Ruby Ru.by (noun): A red crystalline variety
of the mineral corundum, the Ruby is classified among the most
valuable of gemstones. Other crystalline varieties of corundum
are called sapphires, exhibiting every other color except light
red to dark red, which is reserved for the Ruby. Deriving its
color from chromium, Rubies score a 9 out of 10 on the Moh's
scale of mineral hardness, surpassed only by the 10 of diamonds.
Ruby held in the highest esteem, originates from Burma (Myanmar),
which displays a blood-red like fluorescence. Other origins
include Sri Lanka, Vietnam, Thailand and Cambodia.