Many early specimens of taaffeite were discovered already cut and polished, often misidentified as spinel. Over time, ...

Spinel, MgAl 2 O 4 (download cif), is a rare gemstone that was used to imitate rubies. The structure has face-centered cubic symmetry, and is a little heavy to understand. The general formula is AB 2 ...

Would they like something bright, or would they go a bit more, you know, subtle?’ When she first came upon the magnificent cushion-cut grey spinel that now reigns supreme in her latest high jewellery ...