By Helen Serras-Herman
Blue gems comprise a large percentage of colored gemstones, whether transparent or opaque.
Transparent gemstones are commonly faceted, carved, or cut as faceted beads, while opaque gemstones are mostly cut en cabochon, carved, and cut as beads in many shapes and styles. Almost every mineral group contains at least one blue member: corundum (blue sapphire), quartz (chrysocolla in quartz), tourmaline (indicolite), beryl (aquamarine), topaz, spinel, apatite, and zircon, just to name a few.
Blue gemstones came into the spotlight this year, as the Pantone® Color Institute, Inc. announced the 2020 Color of the Year as being Classic Blue. Their description for Classic Blue states, instilling calm, confidence, and connection, this enduring blue hue highlights our desire for a dependable and stable foundation on which we build as we cross the threshold into a new era, referring, of course, to the new decade of 2020.
In recent years, we’ve seen the colors of jewelry fashion are influenced by fashion color trends in clothing, textiles, furniture and home décor. The ideas flow from the runways to the stores. And a driving engine for this movement has been Pantone.
I love reading, on Pantone’s website, the sophisticated names of the chosen colors along with their concise but elaborate descriptions. The color names exude a luxurious feeling, an exotic or natural sentiment that may add some poetic sensation to our jewelry artwork. Designers can find inspiration for new designs within those few words, or tie in already created artwork and give it a new highlight and marketing focus.
Classic Blue - Transparent Gemstones
Besides the ideal option for Classic Blue being blue sapphire, other transparent blue gemstones fit that color shade, such as blue spinel and blue tourmaline. Buyers have to really know or trust that what they are purchasing is what they thought because once faceted, blue gemstones with similar colors are very difficult to visually identify.
Every year during the Tucson gem shows the Gemmological Association of Great Britain (Gem-A) sets up an information booth in the galleria at the American Gem Trade Association (AGTA) show. This year, besides their publications and instruments display, they brought a small exhibit case with eight blue faceted gemstones, for a challenge they called the “Blue Stone Detective,” wherein visitors were asked to identify the stones. To help the visual identification, Gem-A provided flashcards with clues about the gems.
The hints focused on luster, refractive index, or dichroism properties. I must confess, at first glance, I thought that I would completely flunk the challenge, as I don’t perform gemological tests daily, as a jewelry appraiser would. I had to dig deep into my memory bank, as I received my gemology diploma from Gem-A in 1988 when we had to memorize all refractive index and specific gravity numbers. But, I took my time and surprised myself by identifying seven out of the eight stones correctly. The eight blue gemstones were blue sapphire, glass, blue spinel, synthetic blue spinel, iolite, blue topaz, and zircon. The challenge was a great reminder of how difficult it is to visually identify faceted blue stones, without clues or instruments.
One of my favorite transparent blue gemstones is blue tourmaline, known as indicolite. Wonderful, deeply saturated blue crystals come from Brazil and Afghanistan. I have drilled, carved, and wire-wrapped in gold and silver several of them.
Classic Blue - Opaque Gems
The description for Classic Blue matches precisely the rich colors of azurite and lapis lazuli. They are both ancient, timeless gemstones, that have been used as lapidary materials and as ground pigments for personal adornment, and murals over the centuries.
Azurite is a deep blue-colored copper mineral, with the chemical formula,
Cu3(CO3)2(OH)2. Azurite crystals form as dark blue prismatic crystals, but more commonly azurite is found in a massive nodule or stalactitic form. It is very soft, only 3.5-4 on the Mohs scale. Stunning azurite crystals come from copper mines worldwide, including deposits in Morocco, Namibia, Hungary, Greece, Mexico, and of course, Arizona.
Lapidaries use azurite in various forms. When the material is solid, it can be cut and highly polished. Azurite from the legendary Bisbee and Morenci copper mines in Arizona is known to be the most solid, and therefore, the most sought after.
Azurite often shows a unique rosette-structure, which I would call a scintillating pattern, of tiny prismatic crystals moving around in different directions within the surface. That can be cut just like other drusy material, leaving the drusy surface in the center untouched and polishing the surrounding surfaces. Some of the azurite crystals within the drusy surfaces are complete small crystals with very high luster and some translucency, such as the specimens from the Morenci Mine and the mined-out Milpillas Mine, in Sonora, Mexico, which I’ve cut and made into pendants.
Also popular are the azurite “balls,” usually cut or split in half to reveal their crystallized interiors. Beautiful azurite balls come from the famous Morenci Mine, in Greenlee County, Arizona.
I also like the azurite “suns” from Australia (Malbunka Copper Mine, Western Aranda County, Areyonga, Northern Territory), that exhibit a radiating structure and a beautiful texture with high ridges.
Azurite frequently forms together with malachite, which is often a pseudomorph replacement of azurite, and may display spectacular sunbursts or drusy. The two natural minerals make a stunning visual arrangement when cut together as a gemstone, often with a combination of drusy and polished surfaces.
Classic Blue also matches the beautiful blue pietersite from Namibia. Pietersite is a form of chalcedony with embedded fibers of amphibole minerals and varying degrees of alteration. The fibers cause chatoyancy, similar to what’s seen in tiger’s eye, but tiger’s eye is not made of chalcedony, but macrocrystalline quartz (https://www.mindat.org/min-27262.html ).
Pietersite was discovered in 1962 by Sid Pieters in Namibia, hence its name. It is usually found with blue coloration and swirls of gold, brown, and rusty red hues. Pietersite is a favorite gem material of Wolfgang Vaatz, the amazing gem and jewelry artist featured in my Road Report column, published in the February 2020 issue of
Rock & Gem.
With a multitude of blue gemstones to choose from, whether you are cabbing, carving, or faceting, remember to shine an extra spotlight on these gemstones this year, under the Classic Blue Color-of-the-Year banner.