Published: August 2011
by Shawn O'Sullivan, Sr JTV Gemstone Buyer
The name topaz was most likely derived from an island in the Red Sea, now Zabargad but formerly Topazos, which is the ancient source of peridot.
Red and pink topaz gems were used in the jewelry of the 18th and 19th Century Russian Czarinas and earned the name "Imperial Topaz". During the Middle Ages, topaz was thought to heal both physical and mental disorders and prevent death. The Greeks believed it had power to increase strength and to make its wearer invisible; the Romans believed it had power to improve eyesight; the Egyptians wore it as an amulet to protect them from injury.
The most famous topaz is a colorless topaz that was originally thought to be a diamond. It is a 1680-carat stone known as the "Braganza Diamond" set in the Portuguese Crown Jewels. Another beautiful topaz is in the Green Vault in Dresden which has one of the world's most impressive gem collections.
Topaz is composed of aluminum fluorosilicate which contains both fluorine and hydroxyl. The coloring agents in topaz are iron and chromium. Deposits are associated with pegmatite or secondary placers.
Discovered around 1760 in the Ouro Preto (meaning Black gold) district of Minas Gerais Brazil is a mine called Capão that only produces this particular color of topaz. The topaz hailing from this particular area can range in color from a pastel yellow to a rich golden hue. The pink color can range from a peachy pink (also known as Imperial) to a vibrant, bright pastel pink known as Precious Pink Topaz. The pink color is the most valuable of the topaz family which commands a higher price in the market.
Capão Mine is the largest and oldest commercially viable mine for imperial topaz in the world. It is an open cast mine, where weathered topaz-quartz-calcite veins are mined. The gravel is transported by a dredge bucket to the hydraulic washing station. The clay is removed with huge water cannons and the rocks in the material are transported to a belt where the gems are sorted. The result of processing many tons of clay is a few dozen topaz crystals per day.
Blue and golden/yellow topaz are typically irradiated while imperial and pink topaz are heat treated to deepen the color. The pink is carefully heated in a specific environment to drive off the yellow/orange tint and leave the pink color. The heating process is a fine science that must be carefully calculated produce these fine colors.
Care must be taken during polishing and setting of pink topaz because of the danger of cleavage. The best cleaning method is the use of warm soapy water. Avoid using an ultrasonic machine. Also, avoid prolonged exposure to light and heat as well as sharp blows or sudden temperature changes.