spinel

A hard, variously colored mineral with composition MgAl₂O₄, having usually octahedral crystals and occurring in igneous and metamorphosed carbonate rocks. The red variety is valued as a gem and is sometimes confused with ruby.

Any of a group of minerals that are oxides of magnesium, iron, zinc, manganese, or aluminum.

A mineral of various shades of red, also blue, green, yellow, brown, and black, commonly occurring in isometric octahedrons.

A bleached yarn from which the linen tape called inkle is made.

Bleached yarn in making the linen tape called inkle; unwrought inkle.

A mineral occuring in octahedrons of great hardness and various colors, as red, green, blue, brown, and black, the red variety being the gem spinel ruby. It consist essentially of alumina and magnesia, but commonly contains iron and sometimes also chromium.

any of several hard minerals of cubic symmetry that are mixed oxides of magnesium and aluminium and are used as gemstones of various colours

any crystalline material, not necessarily an oxide, that possesses the same crystal structure as this mineral

Bleached yarn in making the linen tape called inkle; unwrought inkle

a hard glassy mineral consisting of an oxide of magnesium and aluminum; occurs in various colors that are used as gemstones