August Birthstone – Spinel, Peridot, Sardonyx


Spinel is #8 on Mohs scale, good toughness. Sources are Cambodia, Myanmar(Burma), Sri lanka, Tanzania, Thailand. Myanmar is known for fine-quality pink and red spinels.

Spinel is a good candidate for the title of “History’s Most Underappreciated Gems.” Some Ancient mines that supplied gems for royal courts, from Rome to China, produced spinels. Yet, they were usually confused with better-known stones like ruby and sapphire.Spinels history dates back to the 1300’s, and it’s a central stone in the British Imperial State Crown.

Modern technology hasn’t helped spinel’s confused identity either. At least as far as the general public is concerned. This is largely due to the widespread use of synthetic spinel as an imitation for many other gems. Most customers don’t even know there’s a natural version of the stone. Limited availability also contributes to spinel’s lack of public recognition. Gem-quality material is typically transparent and faceted, but it’s hard to find in sizes larger than 5 cts.

Spinel’s color range includes violet, blue, orange, red, pink, and purple. Blue spinels are often grayish and subdued, but the best are a deep rich color. The reds can rival fine ruby. The vivid orange to orange-red stones merit their name—flame spinel. Some spinels show color change, usually turning from grayish blue in daylight or fluorescent light, to purple under incandescent light. Spinel is a hard, tough stone that’s suitable for daily wear in any type of jewelry.



Peridot is # 6 ½ to 7 on Mohs scale, fair to good in toughness. Sources are Myanmar, Pakistan, United States.

Peridot has always been associated with light. The Egyptians called it the “gem of the sun.” Some believed that it protected its owner from terrors of the night, especially when it was set in gold. Others strung the gem on donkey hair and tied it around the left arm to ward off evil spirits.  Today, Arizona’s San Carlos Indian Reservation is the world’s most commercially important producer. Peridot is usually transparent. It comes in an attractive range of colors, from brownish or yellowish green, to greenish yellow. People will be attracted to the bright lime greens and more subdued olive greens of this lovely gem. This gem is relatively inexpensive and plentiful, and normally available in standard shapes and calibrated sizes, up to about 5 cts. Larger stones are also fairly easy to find. Tumbled and faceted peridot is used for bead necklaces and bracelets. They are often combined with gems in contrasting colors—amethyst, citrine, and pink tourmaline, to name a few. The word peridot comes from the Arabic faridat, which means “gem”. Most peridot was formed deep inside the Earth and was brought to the surface by volcanoes. Some has also come to the Earth in meteorites, but this extraterrestrial peridot is extremely rare, and you’re not likely to see it in a retail jewelry store. Mineralogists refer to the stone as olivine.


Sardonyx is # 6 1/2 to 7 on Mohs scale and good in toughness. Sources are Brazil, Madagascar, United States, and Uraguay.

Sardonyx is a Chalcedony varieties characterized by straight, parallel bands of different colors. Sardonyx is similar to black onyx, known as red onyx to some people. Sardonyx’s colors range from dark brown to brownish orange or brownish red alternate with either white or black.

Since Greek and Roman times, Sardonyx have provided gem carvers with ideal materials for cameos and intaglios. The color banding allows the creation of carved designs that contrast dramatically with their backgrounds. Sardonyx is also known to be the healing stone and associate with luck and friendship, good fortune, romance, marriage, stamina, energy and creativity and also considered as a stone of protection and strength.

Sardonyx is inexpensive, plentiful and available in large sizes and also traditionally popular for beads, cabochons and tablets. Sardonyx is accepted as one of the US birthstones for August.