Got the Blues? Discover Blue Gemstones
In one of his poems (“Fragmentary Blue”), Robert Frost described how we treasure the color blue. Blue gemstones are a case in point.
Blue gemstones such as sapphire, turquoise, and lapis have been loved and treasured from antiquity to the point that deposits have played out and prices for fine quality stones have gone through the roof. The remaining material has been filled, dyed, waxed, and/or oiled to make it more commercially desirable. The stones are relentlessly imitated.
But while these are the most well-known and most sought-after blue gems, there are many other blue gemstones that can fill your desire for the color.
Blue Gemstones: Sodalite
Found throughout the world, the best known deposits of sodalite are in Canada. In fact, it’s been called Canadian lapis or Canadian Blue Stone. Discovered in 1892 in Bancroft, Ontario, the Bancroft Gem & Mineral Club did their best to have it declared the official emblem of the province, but sodalite lost out to amethyst. On visiting Canada in 1901, the Duke and Duchess of Cornwall fell in love with sodalite and ordered more than 100 tons of the stone to be used to decorate their home, Marlborough House.
Sodalite is most often a by-product of mining for other materials that are used in construction and industry. The small amount mined strictly for the lapidary market is usually made into caliber-cut cabochons, beads, or used for inlay. Sodalite commonly contains white veins of other minerals, and while it is 5.5 to 6 on the Mohs hardness scale—suitable for jewelry—it has six directions of cleavage and can be brittle. During mining and cutting, fractures may develop; it’s not unusual to see fine fractures on the surface of cut stones. When worn in a ring or bracelet, hitting the stone on a hard surface can break it. You’ll want to be careful during setting as well. Avoid buying stones with thin edges that can chip.
Blue Gemstones: Azurite
Another brilliant blue gemstone, that takes second place to no gem, is azurite. The blue is so intense that, like lapis, it was used during the Middle Ages and the Renaissance as a pigment. The problem was over time, with exposure to light and moisture in the air, azurite broke down into malachite, so that paintings from the Middle Ages may show a change in color. The pigment, requiring transportation and laborious grinding, was extremely costly. So it faded out of use when artificial blues were created in the 1700s. Fortunately the gemstones are still around and being cut by clever lapidary artists.
Yet another mineral that owes its sensational color to copper, azurite is also somewhat soft—3.5 to 4 on the Mohs hardness scale—and brittle. So show it off in jewelry other than bracelets or rings. Stabilized azurite may be a bit tougher. Remember, stabilization should be disclosed. However, no ultrasonic, steamer, or harsh cleaners.
Blue Gemstones: Covellite
An amazing stone I found while cruising the Barlow’s Gems website is covellite. It’s a copper sulfide first discovered on Mount Vesuvius, though it’s found around the world. It’s very soft at a 2 on the Mohs hardness scale, but wow! What an appearance! Metallic, indigo blue, with flecks of pyrite in it. This would be a show stopper center stone in a neckpiece. Use extreme caution when setting and cleaning this stone due to its delicate nature, but something this gorgeous is worth the extra attention.
Blue Gemstones: Chalcedony
Blue chalcedony is a subtle stone that has come into its own. Ranging from pale lavender to a rich, violetish blue, it is an excellent foil for other gemstones but can steal the show on its own. Lighter shades can mimic lavender jade. Some of the pieces show a botryoidal surface—like bubble wrap—to give the imagination room to roam. It can be mixed with various shades of blue and white as it is in blue lace agate. By itself, it can be and is used by skilled gemstone carvers to create masterpieces like this netsuke-like mouse.
Chalcedony is a workhorse in the jewelry world because it is hard (a quartz 7 on the Mohs hardness scale), tough, takes a great polish, and comes in a wide variety of colors and patterns.
Blue Gemstones: Larimar
Finally, at the lighter end of the blue spectrum, is larimar. Like the blues of turquoise and chrysocolla, copper causes the color in larimar, a blue variety of pectolite only found in the Dominican Republic. The patterns in the stones make me think of the wavy patterns light casts on the bottom of a pool. So no wonder it’s a favorite in cruise ship gift stores.
The “sleepy” look of the stones is due to pectolite’s fibrous nature. Larimar is soft at 4.5 to 5 on the Mohs scale, so it will scratch easily. It is best as beads or in neckpieces, brooches, or earrings. It’s a bit brittle, so use care when setting and cleaning. It can be corroded by acids and cleaning products, so warm water and gentle soap only. The color can fade in prolonged sunlight, so not a piece you want to wear to the beach—or at the pool on that cruise ship.
If you’ve got the blues, you’ll find a gemstone to suit your mood.
Sharon Elaine Thompson is a GG and FGA who has been writing about gemstones and jewelry for Lapidary Journal Jewelry Artist since 1987. She also writes a line of birthstone romance novels under the name Liz Hartley.