Rubies are formed of a mineral called corundum, comprised of aluminum oxide. The red color is caused by traces of chromium. Corundum also forms sapphire in many colors, which generally come from ...
Sapphire is September's birthstone. This gem belongs to the corundum family. Corundum is inherently colorless, according to the International Gem Society. So, each stone's elemental structure ...
Try a concrete saw. Following is a rundown of common concrete-cutting tasks—from dinky to monster-sized—and the best tools and techniques for handling them. Blades made of corundum may be cheap, but ...
Interestingly, due to the temperature of these worlds the clouds are not made of water, but instead things commonly found as rocks or minerals here on Earth such as enstatite (sand), or corundum (the ...
Like their gemstone cousin the sapphire, rubies are just a variety of corundum, or aluminum oxide. Where sapphire gets its blue tint mainly from iron, rubies get their pink to blood-red hue from ...