Spinel is a good candidate for the title of "History's Most Under Appreciated Gem." Some of the world's most illustrious "rubies" have actually turned out to be Spinel. One of these is the Black Prince's Ruby, a polished but unfaceted red Spinel that weighs about 170 cts. It sits in the Imperial State Crown of the Crown Jewels of the United Kingdom.The stones from Mahenge are a relatively new find from Tanzania. This area has produced some of the brightest and most intense pink and red stones ever seen. Almost all of the Mahenge Spinel on the market today has been cut from one huge crystal that has been broken up and cut into the cleanest possible stones. Spinel Information - Color: Violet, Blue, Orange, Red, Pink, and Purple. Red spinel can rival fine ruby. The best blue spinel is "cobalt blue." (most blue spinels are colored by iron which are usually a low satulation color). Color Change and Star are rare. Hardness: (Mohs scale) 8. Toughness: Good. Heat: Stable. Light: Stable. Chemical: Stable. Major Sources/Origins: Cambodia, Myanmar, Sri Lanka, Tanzania, Thailand (usually black). Other: Afghanistan, Pakistan, Vietnam, Tajikistan. Spinel Enhancement and Treatment: No commercial enhancements. Care and Cleaning: Ultrasonic cleaning: Usually safe. Steam cleaning: Usually safe. Warm, soapy water: Safe. Did you know? Spinels usually come in the same alluvial as corundum (Ruby and Sapphire). Some Spinels show color-change or a star phenomena. "Balas ruby" is red Spinel.