Shades of Blue: The December Birthstones

• December 28, 2018 1:33 pm
• Published by Gallery Byzantium

Those born in December have the benefit of being able to select from three different gemstones, each cherished for its brilliant shades of blue: tanzanite, zircon, and turquoise.   “These gems range from the oldest on earth (zircon), to one of the first mined and used in jewelry (turquoise), to one of the most recently discovered (tanzanite).”  

In previous blog posts, we have explored the history of the ancient turquoise, coveted for its good fortune and protection against evil, and the recently-discovered tanzanite, known for its pleochroic nature.

This week, we’re looking at the zircon which, despite occurring in a rainbow of colors, is best-known for its blue hues.

Celebrating a December birthday or anniversary and see another piece you like that is not set with one of these stones? Not a problem! Give us a call at 800-798-6173 or e-mail us at info@gallerybyzantium. We’d be happy to customize one of our pieces for you!

The Oldest Gemstone

Amulet case with Vishnu Riding Garuda. 17th–19th century. Nepal. Gold, rubies, sapphires, emeralds, pearls, zircon, coral, lapis lazuli, and turquoise. Via metmuseum.org.

Zircon is the oldest mineral on earth; Australian examples date back 4.4 billion years, making the stones older than the moon! It is found in the earth’s crust among metamorphic rocks and crystallized magma.

Though Australia is the leading producer of these stones, they are also found in Thailand, Tanzania, Cambodia, Sri Lanka, Canada, and the United States.

“The name zircon likely comes from the Persian word zargun, meaning “gold-colored.” Others trace it to the Arabic zarkun, meaning “vermillion.” Given its wide range of colors – spanning red, orange, yellow, green, blue and brown – both origins make sense.”  Despite its myriad of colors, blue is still the most popular hue.

To improve their coloring and transparency, zircons are heat treated.  This heat treatment also helps to give a blue color to gray- or reddish-brown stones.  Most naturally-blue stones come from Cambodia or Burma.

Though beautiful in its own right, colorless zircon has been used as a diamond substitute.  Both stones are known for their brilliance and fire and there has been confusion between the two over the centuries.  Unfortunately, with the advent of lab-created cubic zirconium, zircon is thought of as a cheap alternative to diamond.  This is due to the similarity in names between the two stones (though they are unrelated).

Unlike cubic zirconium, however, zircon is a natural gemstone.  It is part of the neosilicate family which includes garnet, beryl, peridot, topaz, quartz, and tourmaline.  It is classified into three types: high, intermediate, and low.  High stones “[…]have full crystal structures, with little or no damage from radioactive elements”(zircon does contain traces of radioactive elements, however these are neutralized during the heating process).  Nearly all stones used in jewelry are of the high variety.  In intermediate stones, these elements have created some structural damage.  Low stones “lack an orderly crystal structure” and have extensive damage from the radioactive elements. These low zircons are usually a green or brown color.  Green is especially rare and, despite its “low” characterization, is quite sought after.

In the Middle Ages, zircon was believed to aid with sleep, ward of evil, and bring prosperity to the wearer.  It was a favorite stone of the Victorians – the blue hue in particular, though smoky grey varieties were used in mourning jewelry.  “Gemologist George Kunz—Tiffany’s famed gem buyer—was a notable zircon advocate. He once proposed the name “starlite” to promote the gem’s fiery nature. The name never caught on.” 

Zircon measures a 7.5 on the Mohs scale.  Though it would seem to be a strong, sturdy gemstone, its faceted edges will chip/break if banged against something.  Though it has been used as a natural substitute for diamond, this chipping means that it probably shouldn’t be used in rings (and, if it is, said rings should be worn with care).

Zircon should be cleaned carefully with warm water and a mild soap or detergent.  It should never be steamed (which could affect the color) or cleansed ultrasonically (due to its brittleness) and should not come in contact with harsh cleaning agents like bleach.

Sources

Main image via https://www.gia.edu/zircon-description

December Birthstones – https://www.americangemsociety.org/page/decemberbirthstones
Zircon Description – https://www.gia.edu/zircon-description
Zircon History and Lore – https://www.gia.edu/zircon-history-lore
The Gemstone Zircon – https://www.minerals.net/gemstone/zircon_gemstone.aspx
Zircon Gemstone Information – https://www.gemselect.com/gem-info/zircon/zircon-info.php

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