This is a beautiful thumbnail size Spinel from Mahenge, Morogoro Region, Tanzania.
Crystal Dimension: 2.3 cm (0.9”) x 2.2 cm (0.87”)
Crystal Weight: 7.6 grams
Spinel is a mineral that owes its beautiful color to chromium, much like rubies and emeralds do.
The chemical formula for Spinel is:
MgAl₂O₄