Spinel is a very aesthetic and historically important gemstone mineral. It has a vitreous luster and occurs in almost every color; pink, blue, green, purple, lavender, brown, black and by far the most common color, red. Known as Ruby Spinel, it is the most desirable and valuable of all the colors. It is often paired with Marble and Calcite, creating a striking contrasting specimen.

The crystal system for Spinel is isometric, commonly forming octahedral crystals, often perfectly shaped; sometimes with complex faces. Other forms include crystal clusters, rounded and twins.

This gem mineral is relatively rare, with quality specimens/crystals found in limited localities, including Afghanistan, Burma (Myanmar), Canada, Italy, Sri Lanka, the USA (New Jersey, New York) and Vietnam.