Ruby
Ruby forms in prismatic tabular, bipyramidal, or rhombohedral crystals, as well as granular or massive habits, and has a vitreous luster. The most valuable and desired Rubies are those of a shade called “pigeon’s blood,” defined by William Fernie as “a pure deep, rich red, without any admixture of blue or yellow,” though others define it as “a pure red with a hint of blue.” Ruby is red Corundum, an aluminum oxide mineral with chromium responsible for its rich, red color. The name comes from the Latin word Rubeus, meaning “red,” and until 1800, when Ruby was recognized as a variety of Corundum, red Spinels, Tourmalines, and Garnets were also believed to be Ruby.
