The stone for strength and success, topaz has been valued throughout history for its magical prowess, not to mention its beauty. In fact, the ancient Greeks believed that if you wore topaz it could prepare you for future hardships and also could increase your strength, and even more interestingly they believed that topaz would provide the power of invisibility. Although blue topaz may be the most common variety found in retail stores, consumers wouldn’t always be aware that this colour is rarely found in nature and stones are almost always colour enhanced – some consumers may not even know that other colours exist. Topaz can come in a variety of colours such as red, pink, blue, green, colourless and even brown.
Known as the November birthstone, the name topaz was derived from an island in the Red Sea “Topazos”, today called Zabargad, the ancient source of peridot. This gem is an aluminium silicate with varying amounts of fluorine and hydroxyl. Although this stone measures a high 8 on MOH’s scale of hardness it is not necessarily a ‘tough’ stone due to its perfect basal cleavage. Cleavage refers to a stone’s tendency to ‘cleave’ or ‘split’ along certain crystallographic structural planes due to a weakness in their atomic bonds. Although a gemstone doesn’t necessarily become weak because of perfect cleavage, the gem cutter and jeweller must practice caution to ensure cleavage does not occur. In topaz’s case, the cleavage occurs in one direction parallel to the basal plane and stones are best cut at a 12-15% off this cleavage plane.
Crystallising in the orthorhombic crystal system, topaz crystals are generally well-formed prisms with striations parallel to the c-axis (length of the crystal). Crystals are terminated with domes and pyramids which make them easy to confuse with danburite which shares an almost identical crystal form. Topaz crystals occur mainly in felsic igneous rocks such as granite, granite pegmatite and rhyolite and often found in veins and cavities in such rocks. When fashioned, topaz gemstones (particularly blue/colourless) are often free of visible inclusions or flaws and, because of their elongated crystals, stones are mostly fashioned into pears, ovals and rectangles to yield more carat weight.
Topaz, when in its purest state, is colourless and owes its varying hues to impurities, defects in the crystal structure or enhancements by the gemstone industry rather than an element of its basic chemical composition.
In nature, topaz is mostly commonly colourless with naturally occurring strong blue gems being extremely rare. In the marketplace they are plentiful due to colour treatments being common practice. A combination of radiation and heat has been used to produce blue hues since 1970. This irradiation is perfectly safe as a “cooling down” period is taken into account. This is an acceptable treatment and should be assumed for all blue coloured topaz gemstones. The deepest of blues with a slight green tone is known as “London Blue”, a vivid medium blue is known as “Swiss Blue” and (my favourite) a light but bright icy-toned blue is known as “Sky Blue”.
Imperial topaz is a golden yellow, pink to orangey-red colour and colours are due to the presence of iron and chromium. First discovered in the Ural Mountains in Russia during the nineteenth century, pink and red topaz were reserved exclusively for the family of the czar hence its ‘imperial’ title. Today industry dealers state that stones must exhibit specific pleochroic colours to be classified as imperial topaz otherwise they are simply named golden topaz as they lack the prized overtones.
Bunny Bedi, owner and director at Made In Earth Creations discusses his newest gem to his ever- growing collection. “Imperial topaz is something we’ve always been asked for however the colour and price of citrine has always been more desirable to our clients… until now. The delicate honey hued topaz crystals are the perfect addition to our collection and this November birthstone has arrived right in time!”
If you are looking for the largest crystals in the world, topazis your gem with some of the heaviest crystals weighing 600 pounds (You can find this beauty in the Museum of Natural History in New York City, USA). Topaz is a beautiful crystal with breathtakingly beautiful clarity and electric colour of this treated stone. As long as treatments are disclosed then this stone is all right by me.