We have a birthday present for those born in August: the stunning spinel has been added to your month’s birthstone lineup! August now joins June and December as the only months represented by three gems.
The original birthstone for August was Sardonyx, and then peridot was added, becoming August’s primary gem. Now spinel adds its multitude of color choices!
The spinel is often assumed to be other gemstones because it tends to resemble either a ruby or sapphire. 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 gems. 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 U.S.
Vivid red is the most desirable color of spinel gemstones, followed by cobalt blue, bright pink and bright orange. The more affordable stones 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. So many choices!
In the gem world, spinel could easily earn the title of “Most Underappreciated Gem.” Throughout history, spinel was often confused with ruby and sapphire.
Mines of central and Southeast Asia yielded large spinel crystals known as Balas rubies, which became valuable property of emperors and kings, and often passed along as the spoils of war.
Some of the most famous rubies in history have turned out to be spinel. Large red gems, such as the “Black Prince’s ruby” and the “Timur ruby” in the Crown Jewels of England have confirmed to be large red spinels.
Many English monarchs, including Henry VIII, have prized spinel. It has survived them all, through attempted theft, bombings, and fires!
One member of the spinel group, magnetite, has magnetic properties. As early as the 11th century, mariners used this form of spinel known as lodestone to magnetize their compasses.