Gem Profile Nov. 16: Blue Topaz
by Layna Palmer, Wire-Sculpture.com
I’m feeling a little "Blue" today, it’s quite "Mystical" that I’m feeling this way, perhaps I’ll be able to feel in the "Green" again if we finish our talk about Topaz! As we learned last week, Topaz is a naturally colorless stone, but due to inclusions and imperfections can range in color from clear to yellow/gold, green and blue.
Blue & Green Topaz
Blue Topaz, in all its varied shades, is rare in nature. This means that lighter-colored stones are enhanced through radiation and heat to change the color. There are a few deposits of naturally Blue Topaz throughout the world, one being in Mason County Texas. A recent find at the Zapot mine in Hawthorne, Nevada has given us more natural light blue and pale green Topaz.
Since Blue Topaz is not really found much in nature, why is there so much available for purchase, you ask? Well, the simple answer is; Science! Clear or lightly colored Topaz is bombarded with neutrons, electrons or gamma rays to realign the crystal matrix and enhance or change the color of the stone. The stones are then heat treated to stabilize and set the color. (Some naturally-blue stones will lose their color over time – treated stones are less likely to fade).
How was Irradiation Discovered, Anyway?
The first known irradiation of a gem was in 1905 when an English Chemist, Sir William Crookes, buried a diamond in radium bromide powder. Sixteen months later, the previously colorless diamond was a beautiful shade of green – but highly radioactive! This process for coloring gems is no longer in use. Now, color-enhanced gems sold in the United States are regulated.
Types of Blue Topaz
The most sought-after color of blue in Topaz is the deep London Blue which is created by neutron bombardment of the stone then heat treating to remove any residual yellowing and stabilize the color. Sky blue Topaz, a color similar to light aquamarine, is created in a linear accelerator with electrons. The medium-blue color of the Swiss Blue Topaz is created when both processes are used on the stone.
Green Topaz stones are created by the stone changing color after irradiation during heating. Usually only darker yellow or light pink topaz stones turn green under these circumstances.
Mystic Topaz is another type of Topaz that is a natural stone with a titanium coating on the pavilion that reflects light and creates the green, blue, purple and red flashes that make Mystic Topaz so beautiful. This patented process is generally applied to clear stones, but other colors of Topaz are sometimes used with different and beautiful results like the Azotic Topaz from last week. Since this is a vapor-coated stone, the care should be similar to that of pearls.
Blue Topaz in Culture
Topaz is one of the Hindu sacred stones and is said to sharpen intelligence and lengthen life if worn as a pendant. Some African tribes use Topaz to commune with ancestors and the spirit world. Blue Topaz works to enhance creative energy, bring fortune, help in concentration, and is a symbol of uprightness and virtue. Wearing a ring of Blue Topaz is said to ward off premature death and can control greed or lust. There are legends of Topaz losing its color in the presence of poison, thus protecting its owner. Blue Topaz is also the alternative birthstone for December.
The Lone Star Gem
Another road trip? Let’s go to Texas! Blue Topaz is the state gem of Texas and even has its own gem cut known as the Lonestar cut. The light blue stones were called "desert ice" by early settlers because of the "icy" appearance of stones found in streams. Though Texas Topaz isn’t mined commercially, if you’re willing to put in a little work and get a little dirty, you can find them yourself.
Next Friday’s Gem Profile is on moissanite. If you’ve had the fortune to wrap moissanite in wire, or if you have any moissanite specimens, please send pictures to firstname.lastname@example.org, and they could be featured!
Resources & Recommended Reading
- Topaz – Minerals.net
- Topaz – My Gemologist
- Blue Topaz History
- Mystic Topaz
- National History Museum Adopt-a-Mineral (PDF Download)
- Gemstone Irradiation
Gem Profile by Layna Palmer
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