Spinel

Do not be fooled by those old high school class rings that contain synthetic spinel into thinking this is the flagship for all spinel: this could not be further from the truth.  Natural Spinel is one of the most amazing gemstone and extremely valuable.  In fact, discovery of new deposits in Tanzania bring very hefty price tags; especially 'Candy Apple Red'. 

For many decades, Spinel was actually thought to be corundum. Spinel comes in a huge variety of colors depending on the impurities, similar to corundum. Red spinel is mostly colored by chrominum and iron.  Blue spinel is colored by iron and sometimes cobalt.   Other colors include green, brown, black, lilac, purple, orange, orange-red, rose and nearly colorless.  Most common sources of Spinel include Myanmar (formerly Burma), Sri Lanka, Madagascar, Tanzanai, Migeria, Brazil, Russia, Pakistan, Thailand, Italy, Turkey, USSR, Sweden and USA.   Spinel ranks 8 on the Mohs hardness scale.   Spinel is a very durable and brilliant gemstone.  It's excellent value for the money.

Spinel's composition is 'Magnesium aluminum oxide, with a RI of 1.71-1.73. SG: 3.60. Spinel's crystal structure is cubic, usually appearing in octahedral form.  indinsticht cleavage and vitreous luster.