brandyzzyzx:

Corundum var. Ruby
near Upland, Cascade Canyon, California

Twice a month our Gallery sponsors a free, guided monthly, public mineral collecting trip. This Sunday we went ruby collecting in Cascade Canyon, California. We had a wonderful turn out, over 20 people! The weather was warm and sunny, and everyone found plenty of specimens to take home. This is one of our most popular mineral collecting trip locations. Below is a map to the location.
View Corundum of Cascade Canyon in a larger map

pyromorphite:

Rubies are a variation of Corundum, Aluminum Oxide, in which Chromium replaces Aluminum (the Chromium give Rubies their colour.) The term Ruby is only used for the red variety of Corundum.

schisthappens:

Corundum
Formula: Al2O3
System: Trigonal
Hardness: 9
Name: Derived from the Sanskrit, kuruvinda (“Ruby”).

The red (Cr-bearing) gem variety is called Ruby.

The blue (Fe and Ti-bearing) gem variety is called Sapphire.

mineralia:

Corundum from Tanzania

thisthirdeye:

corundum