Topaz Key Facts
- 8 on the Mohs scale of hardness
- Often blue, but available in other colours including pink, yellow and brown
- December's birthstone
- The astrological birthstone of Sagittarius and the hour stone of 4pm
- Said to bring imagination to the owner
General Information on Topaz
Topaz has been well known and used since ancient times, although it was probably known by another name as one theory suggests that the name comes from the Island of Topazos, in the Red Sea, where the Romans obtained a yellow stone which they called topaz, but which was actually the modern peridot or olivine. Another theory says that the name topaz is derived from the Indian Sanskrit word tapas, meaning fire. Either way, it also seems to have roots in the Old English and Old French word topace. The first use of the modern word topaz occurred in 1737 and was used to refer to abundant yellow crystals which were found in Germany. In fact, although in the Middle Ages the word topaz was used to describe any yellow gemstone, it is only properly used nowadays to describe this particular stone.
Topaz is an aluminium fluorite silicate containing fluorine and has a chemical formula of Al2F2SiO4. It is one of the few gem minerals which, under suitable conditions, can grow into enormous crystals. In 1944 a 350 tonne crystal was reported to have been found in Mugui, Brazil. Crystals are lozenge shaped in cross section, and any striations run parallel to its length.
Topaz typically occurs in cavities in rhyolites and granite, in pegmatite dikes, and in high-temperature veins as it is formed by the vapours given off in the crystallisation of these particular igneous rocks. It is generally found together with cassiterite and tourmaline all over the world, including in the gem gravels of Sri Lanka where it is recovered as a by-product in the mining of sapphire. Mining is often a hand operation, and the total output per day is quite small, contributing to the relative scarcity of these stones (considering how widely it is found).
Topaz is most often transparent with a vitreous lustre, although this is not always prized in jewellery terms. Light yellow, amber-gold, and brown stones (often known as sherry topaz) and also pink varieties of topaz are valued as gemstones and tend to come from Brazil and Sri Lanka. Some varieties of clear topaz can be irradiated to various shades of blue, and this acceptable in the trade; most blue topaz on the market today is irradiated. There is also a greyish variety of topaz that is sometimes cut to produce a stone called champagne topaz. Clear topaz sometimes has a cloudy or cat's eye effect.
Blue topaz is rare in nature, but is easily created from clear material. There is an abundance of it on the world market, and very large, flawless stones are easily available. It is not a hugely expensive stone so makes a good choice for an affordable engagement ring. It is available in shades of blue from very light, through sky-blue, and on to almost an inky blue. Overtones of grey are not desirable in these pieces, and tend to reduce value. Blue varieties are one of the most popular and widely used gemstones in jewellery today despite the fact that it was only really this century that it began to be used. This may well be due to the escalating price of aquamarine, and the need for a less expensive blue gem on the marketplace.
Red-brown topaz is more common than the natural blues and is found in Mexico and Utah; some can make a nice faceted stone, although some don't. It is sometimes called root beer topaz. Again it is not of highest value. It is typically more expensive than citrine, but far less than morganite, or a good golden sapphire.
Imperial topaz is the most highly prized, and is a red-orange to a pink-orange colour. The colour is due to the presence of hydroxyl ions, and as a result this variety is heat sensitive, and usually contains numerous flaws. Preferred colours make this stone about the same in value as good aquamarine.
Natural pink topaz is fairly rare, but highly valued. It tends to come from Pakistan and Russia. Green is another rare colour, but also highly valued. Although pink is occasionally found in jewellery, the green is very rarely found.
Very clear (white) topaz can be confused for diamond, especially in small side set clusters, and is often set in its place (particularly in jewellery from the far East). It is much less brilliant than a diamond, however, and has much less fire in the sparkle. A refractometer can tell them apart if you've got access to one! (Topaz is double refracting; if you look through it you will see the image the other side twice. Diamonds have a higher refractive index and therefore split white light into rainbows = fire and glitz) Topaz can be distinguished from quartz as it is heavier (has higher specific gravity) and has a higher refractive index than the quartz. Small, set stones, however, can be difficult or impossible to distinguish with the naked eye. One of the features of topaz is its pleochroism (an ability to change the colour of the crystal depending on a direction of light). This property is often quite strong in pink and wine-yellow topaz but is weak for light-blue ones. All this shows that topaz can made a highly affordable alternative to diamond when used in a cluster design - don't forget that your topaz can always be changed for diamonds at a later date, should finances allow!
Topaz comes in a variety of colours but smoky quartz (under the name smoky topaz), or citrine (under the name Bahia or Madeira topaz) is sometimes sold as a variety of topaz to increase the value of the quartz. In purchasing a yellow stone labelled topaz the buyer should always insist on verification and guarantee of the authenticity and natural origin of the stone.
An excavation of one of the oldest primitive man camps found products made of crystal and topaz called nuclei. Archaeologists believe that these narrow blade-like plates could be used both in housekeeping and religious ceremonies as well as for ornaments.
Among other ancient ornaments the Gizella Necklace is world famous, made in 10th century with wonderful topaz.
The Braganza stone decorating the Portuguese royal crown is a large colourless topaz weighing 1680ct and is known under the name 'Large Diamond' as it was mistakenly accepted for diamond for a long period of time.
The largest faceted gemstone ever recorded is the Champagne Topaz. It was mined in Brazil, weighs 36854ct and measures 34.9 x 15.5 x 12.1 cm. The Brazillian Princess is a stunning, slate blue faceted stone which measures 14.5cm across and weighs 21005ct.
There is also a beautiful topaz in the Green Vault in Dresden, one of the world's most important jewellery collections.
In ancient times, a figure of a falcon carved on a Topaz was thought to help earn the goodwill of kings, princes and magnates.
Topaz is the patron of the planet Mercury. It is said to compliment the characters of those born under Leo and Sagittarius and is the birthstone for those born in November.
According to the Bible, topaz is one of twelve precious stones which the High Priest's breastplate was decorated with during the worship of Jehovah, but whether they were referring to actual topaz or another stone is debateable.
The Greeks believed topaz enhanced strength and made its wearer invisible in times of emergency. The Egyptians said that topaz was coloured with the golden glow of the mighty sun god Ra. This made topaz a very powerful amulet that protected the faithful against harm. The Romans associated topaz with Jupiter, who is also god of the sun - in both cases golden yellow topaz was therefore especially valuable.
During the Medieval period it was thought to heal physical and mental disorders as well as prevent death. During the Renaissance, Europeans believed that topaz could break magic spells and relieve anger. In India, many believed that topaz worn above the heart assured long life, beauty and intelligence.
Legend has it that topaz dispels all enchantment and helps to improve eyesight. Topaz was also said to change colour in the presence of poisoned food or drink. Its mystical curative powers waxed and waned with the phases of the moon and it was also said to cure insomnia, asthma, and haemorrhages.
Topaz was widely used in manufacturing various products, weapons and utensils for Tsars, princes and boyars. The large yellow topaz that is best known decorates the famous Cap of an empire of Kazan alongside two pearls. This crown was made under the order of Ivan the Terrible in 15th century in honour of the conquest of Kazan.
Topaz has a hardness of 8, so should really be kept separate from other jewellery to avoid scratches and is a good choice for an engagement ring. Like diamond though, it can be split by a single blow, so it should be protected from hard knocks.
Natural colours (in particular browns) often become paler if kept out in the sun and/or heat so if you're not wearing topaz very often, don't leave it on the window sill in the sunshine!
Do not clean topaz in an ultrasonic cleaner; the best way to do this is warm soapy water and a baby's toothbrush. Large temperature changes will fracture the crystal so are best avoided.
In 1750 a Parisian jeweller discovered that the yellow Brazilian topaz becomes pink on exposure to a moderate heat, and this treatment has since been extensively applied, to the extent that nearly all the pink topaz occurring in jewellery today has been heat-treated.
Topaz has not been synthesized in the laboratory on a commercial basis. So-called 'synthetic topaz' is actually synthetic corundum that has been made in a suitable colour.
Topaz is the state gemstone for Texas.
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