How abundant is the mineral ruby?

Answer 1

Ruby is not a mineral in its own right, it is a variety of the mineral CORUNDUM. Ruby is the name given to corundum (aluminum oxide) which is coloured red by having small amounts of chromium as an impurity (blue sapphire is corundum with iron and titanium). Ruby is found in many areas around the world but only in small ammounts. Ruby good enough to cut into gemstones is VERY rare. So rare in fact that the price the prices per carat of fine rubies are the highest of all gemstones including diamonds.