The spinel is often mistaken for either a ruby or pink sapphire, as it can resemble both. In fact, some of the most famous rubies in history have turned out to be spinel. But its distinguishing features, like its octahedral crystal structure and single refraction, are what sets it apart from other gemstones. Spinel also has a lower Mohs hardness than ruby and sapphire.
Significant deposits of spinel have been found in Cambodia, Myanmar, Sri Lanka, and Thailand. It has also been found in Afghanistan, Australia, Brazil, Madagascar, Nepal, Nigeria, Tadzhikistan, Tanzania, and the United States.
Vivid red is the most desirable color of spinel gemstones, followed by cobalt blue, bright pink, and bright orange. The more affordable gemstones are often those with paler colors, like lavender. You may also find spinel in black, violet blue, greenish blue, grayish, pale pink, mauve, yellow, or brown.
When shopping for spinel, a high-quality gemstone should have no visible inclusions. The more inclusions, the less valuable the gemstone. Spinel birthstones can be found in various cuts such as octagons, trillions, squares, rounds, ovals, pears, and cushions.