Spinel

Structure Crystal axes and Angles Optic Character Refractive Indexes Optic Sign Pleochroism Examples Amorphous No orderNo axes IsotropicSingly…

In crystallography, mineral habits refer to the way crystals form within a specific mineral. In A Guide to Gem Classification, I mentioned that,…

Crystallography explores stunning mathematical concepts you can see in nature and art. In this article, we’ll discuss crystallography…

Adamantine. Silky. Greasy? Gemologists and mineralogists use these and other evocative terms to describe luster. This simply means how the surface…

Many factors can contribute to a mineral’s color. However, some minerals can have many different colored varieties, while others only occur…

Most gems form naturally as minerals within the Earth. Most form as crystals, solids whose atoms are arranged in highly ordered repeating patterns…

Have you ever wondered where mineral names come from and what they mean? This article will cover the origins of mineral names and discuss the principal…

We live in a world of crystals. You don’t have to dig deep into the Earth to find them. Even the bones in our bodies and the dust in the air contain crystals.…

What comes to mind when you think of crystals? Many people might visualize beautiful, mineral objects with smooth faces in regular geometric patterns.…