There may be some dispute among gemologists about which color and pigment shift the corundum crystal gemstone from being labeled ruby to sapphire. Rubies and sapphires are both made from corundum...
Category: Rubies
Ruby is a red gemstone that is often used as a stone in rings. It's called a ruby because of its color, hardness, and how it was formed: by crystallization of corundum (aluminum oxide, which can form...
The stones ruby and sapphire are both considered precious gems. They share many of the same qualities, but there are some differences between them as well. For example, sapphires come in various...