Gem of the Month: Turquoise

December 11, 2006

tur_cab.jpgThe modern birthstone for December is Turquoise (traditional or alternative birthstones include blue topaz, zircon and tanzanite).  The example at left shows a beautiful sky blue colour with a dramatic black diagonal slash – from Aztec Moon.

Gemmology Matters:  Turquoise is a hydrated copper-aluminium phosphate with the chemical formula CuAl6(PO4)4(OH)8·5H2O.   Turquoise is a cryptocrystalline opaque mineral which is rare in gem quality.  Colour ranges from white through various blue colours to a yellowish green with the most valuable types usually considered to be a pure sky or “robin’s egg” blue with little green tone and even colour.   Colour type depends on the relative amounts of copper and iron in the stone with copper producing blue colour and iron producing green.  Although uniformity of colour is prized in turquoise, it is often found with brown/black veining or marks running through the stone – known as “Turquoise Matrix”, these types are usually worth less but may be considered more attractive by some buyers.

turqbluegem.jpgTurquoise is mined in the Southwestern United States, Iran, Tibet, and China.  Turquoise is usually found in dry regions and in association with copper deposits.  Particuarly in the USA, it is often mined as a by-product of copper mining.   Photograph at left shows a piece of turquoise from Nevada (image from Skystone Trading).   Australia is not a major source of turquoise with only small deposits found in northern Victoria, in the Narooma-Bodalla region of the New South Wales south coast, and at Amaroo station in the Northern Territory (Australian Museum).

Turquoise in its natural state is relatively soft at 5 to 6 on the Moh Scale.  It can be susceptible to damage or discolouration if exposed to prolonged sunlight, skin oils or chemicals in perfumes, cleaning agents, etc.  In order to protect against this, many turquoise gems are sealed with oil or wax.  A more radical form of this treatment is the creation of “bonded” or “stabilised” turquoise by impregnating the stone with epoxy or plastics under pressure.  Some turquoise is sold as “reconstituted” where small fragments of stone are ground and then bonded together to form a new stone – be aware that these types may include “filler” material and/or be dyed.  Imitations are also frequently used – the most common being white howlite dyed to imitate the blue of turquoise.  The cheaper turquoise used in beads or low-cost silver jewellery is usually heavily treated or may actually be imitation.  Very fine quality turquoise is rare and will command a high price – these stones should be verified by an expert.

Mythology and Lore:  Turquoise is among the worlds oldest known gemstones – many ancient civilisations valued it highly.  The name Turquoise is derived from the French “Pierre Turquois” meaning Turkish Stone as it was thought the gem came from Turkey.  Actually, the gems reaching Europe at the time came via marketplaces in Turkey from Persia (now Iran), where some of the oldest known turquoise mines are located.  In Persian, Turquoise is known as “Ferozah”, meaning victorious and it is the national gemstone of Iran to this day.

Ancient examples of its use survive to this day and it may seen in some of the most famous archeological artifacts.  The gold burial mask of Tutankhamun is heavily inlaid with gemstones of which turquoise features prominantly. The Aztecs also used the stone heavily and a number of examples of this work may be seen in work dating back to the time of Montezuma.

serpent.jpgtut.jpgImage at left is of Tutankhamun’s Burial Mask – courtesy of the Egyptian Museum.  Image at right is of an Aztec double-headed serpent with turquoise mosaic – see the British Museum image collection of artifacts from Montezuma’s Treasure.

Many Native American peoples used the stone as a protective amulet – it is often associated with the sky and wind.  It is said that Apache warriors believed wearing  turquoise would improve their hunting prowess.  Turquoise was generally believed to bring happiness and good fortune to all and in fact, it did bring great fortune to the Anasazi people who mined the stone due to the high demand for it from other areas such as Mexico.

The typical Native American turquoise set silver jewellery is a relatively modern development (thought to date from the late 1880’s) – traditional pieces were more likely to use turquoise as beads, inlay or mosaic on natural materials such as wood and carvings.

tur_brac.jpg

However these days, the use of silver to complement the unique beauty of turquoise is closely associated with southwestern American culture and the popularity of this style of jewellery has spread worldwide.  This wonderful example of a handwrought silver bracelet is by Harry H. Begay and is available from Chacadog.com – it is not cheap but the quality of the workmanship and materials deserve no less.

Alternatives in Blue:  Blue is an extremely popular colour for gemstones and there are a range of other gems in blue or blue-green.  For transparent gems, we suggest blue topaz, blue zircon or aquamarine.  Although sapphire from our mine tends to be more saturated in colour, it is possible to buy sapphire in these sky-blue shades as well.  While topaz and zircon are reasonably affordable, you will pay quite a bit more for sapphire or for aquamarine of good (not washed-out) colour.  Blue alternatives in opaque gems might include chrysocolla, agate, lapis lazuli and other similar stones.

Links of Interest:

Hope you enjoyed this article on turquoise – stay tuned for the next gem of the month.

cheers from Aussie Sapphire

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Kashmir Sapphire

November 30, 2006

Came across this interesting snippet of news a few days ago.  If you are interested in mining for the most sought after sapphire in the world, you may be interested in this upcoming tender:

Global tenders for sapphire extraction in Jammu and Kashmir

The problems of mining in such an area are obvious but perhaps the rewards would be very great for someone with the right experience and the ability to work cooperatively with the locals.  Our hope is that the people of the area benefit from these plans rather than see the wealth disappear without consultation or involvement in the scheme.

Genuine Kashmir sapphires are renowned for their beauty and for being very difficult to obtain – perhaps the difficulty of supply might change for the better.

cheers for now from Aussie Sapphire


Newsletter Dec’06

November 25, 2006

Hi all,

Plenty of time left for shipping all your needs for the perfect Gemstone Christmas.

New stock:  After being asked time and again we have decided to offer full Mine Run Sapphire,the real thing with no specials removed, just $5 AUD/ ct.  Unbeatable value for the serious Gemstone enthusiast.  More mine run parcels of quality Tourmaline, Spessartite, Emerald have also been added with  small parcels at large parcel prices – check them now as next stock will be dearer.  Just check out the new Parcels of Rough category.

We have also added more great individual sapphire rough including some very affordable pieces – still great quality so take a look at these new items.

Christmas special is a 20% discount on all our handmade Gold Jewellery.  A great gift idea for the special person in your life.  Truly unique one off designs at 40-50% off  High Street Retail prices.

Andrew’s Christmas picks:  If you cant see anything above, try these super deals:

  • Gem carat electronic scales just $36 AUD – weighs to 0.05 carats, great value, warranty etc.
  • Diamond powder for faceting  20cts just $26 AUD Hard to buy this cheap – proven quality.
  • Bag a beauty fossicking wash, great for young and old,fun and find guaranteed!! (Aussies only only sorry, overseas buyers look at the concentrated gravel). Check our Fossicking link.  Have fun!

Dont forget free Shipping for combined purchases over $100 AUD – just enter free_shipping in the box at the checkout (Redemption Code) to redeem this offer.

In the TRADE ?  Dont miss out on possible further discounts, ask today.

We have been spending a lot of time listing new products so please take a look – I am sure you will find something of interest.  Courier delivery is available so plenty of time to arrive before Christmas.

cheers for now from Aussie Sapphire

  


Black Spinel: Dark Star

November 17, 2006

Just came across this article in Modern Jeweler on Black Spinel:

Black Spinel: Dark Star

The article points out the benefits of using black spinel as a superior alternative to onyx or diamond and highlights some jewellers/dealers who have already discovered this fantastic gem.

“Braunwart (Columbia Gem House) is convinced many jewelers will resist the temptation to be onyx-wise and spinel-foolish. “The large difference in quality should outweigh the small difference in price,” he says”.

Here at Aussie Sapphire, we have been trying to tell the story of Black Spinel for some time.  So far, the feedback is very encouraging and we hope to see even more demand for this wonderful gemstone in the future.

Aussie Sapphire can supply black spinel at very competitive prices:  Retail price =  $6.50 AU/carat for faceted stones < 1 ct in size and only $4.90 AU/carat for faceted stones > 1 carat makes this a very affordable alternative.  Wholesale discounts are available to trade buyers.

Please browse our extensive range of black spinel calibrated gems – not everything is listed so please contact us any time to discuss your requirements.

cheers for now from Aussie Sapphire


Gem of the Month – Yellow Topaz

November 12, 2006

imperial.jpgYellow topaz is also known as the modern birthstone for November.  Although now probably overtaken by the more commonly used Citrine, Topaz is a particularly lovely gemstone which is deserving of more recognition in its “precious” form.

Photo at left from is a good example of Imperial Topaz from Mineral and Gemstone Kingdom

Gemmology Matters:   Natural Topaz is a fluro silicate with the chemical formula Al2SiO4(F,OH).  It is found in a variety of colors including brown, red, orange, pink, sherry, yellow as well as colourless.  Often the shades from yellow through to red are termed “Precious Topaz” with particular colour combinations described as “Imperial Topaz” – those gems denoted as Imperial and the very rare red varieties command the highest prices.  The definition of Imperial Topaz colour (reddish-orange?) can be quite complicated – see this Gemology Online thread for more discussion on this subject. 

sherry_topaz.jpg This example of a sherry coloured topaz crystal is from John Betts Fine Minerals (Gem Crystals catalogue) – this specimen is from Pakistan and shows the hexagonal crystal habit of topaz very clearly.

Green and blue topaz are naturally very pale, the very bright colours often found in jewellery today are the result in irradiation treatment – Sky Blue, Swiss Blue and London Blue are names used by the gem trade to refer to the depth of color.   See our Blue Topaz article for more information.   Please note that surface colour coatings are becoming more common in Topaz – starting with the multi-colour version of Mystic Topaz, but now also used to create other colours such as pink.  Gems treated in this way should be treated with care to avoid damaging the colour coating.  These types of gems should be far cheaper than naturally coloured stones so be wary when purchasing brightly coloured Topaz and ask about enhancement treatments first.

The principal sources for topaz is Brazil – also found in Sri Lanka, Russia, Australia, Africa, Mexico and Pakistan.  Topaz is an excellent gemstone for jewellery with a hardness of 8 – although it has perfect cleavage which may present some danger when setting in jewellery.  For this reason, topaz should be treated with care and protected from hard knocks.

Mythology and Lore:   While the blue variety of topaz is for those born in December, yellow topaz is the modern November birthstone.  Topaz may be given to celebrate the 4th, 19th and 23rd wedding anniversaries.

Most of the mythology for topaz relates to the yellow variety as natural blue topaz is quite rare and pale in colour.  The Egyptians believed that topaz was coloured with the golden glow of Ra – the sun god.  The importance of Ra made topaz a very powerful protective amulet for the faithful.  This link with the sun was also found in ancient Roman culture where topaz was associated Jupiter, also a God of the Sun.

Topaz was once thought to strengthen the mind, increase wisdom, and prevent mental disorders.  It was also thought to guard against sudden death.  Legend says that topaz has the power to dispel all enchantment and help improve eyesight.  The ancient Greeks used the gem to increase strength and make its wearer invisible in times of crisis.  Used in medicine in ancient time, topaz was said to cure insomnia, asthma, and hemorrhages.

imperial-topaz.jpg This imperial topaz photograph is from the Palagems Topaz Buying Guide which also has some excellent information on the famous Ouro Preto mine in Brazil (see link below).

Alternatives in Yellow:  The range of colour in Precious Topaz brings to mind the amber gold of fine cognac, the blush of a ripe peach and all the colours of a setting sun.   While its cheaper cousin, Citrine, is commonly used these days and is an alternative November birthstone, it is slightly softer and does not have quite the complexity of colour that is present in a particularly fine Topaz.  Sapphire is also found in yellow – while beryllium treated yellows now abound in the marketplace, a fine golden yellow sapphire of natural colour can command very high prices. 

Links of Interest:

Aussie Sapphire does not currently have any topaz in stock – we do have a small supply of good yellow sapphire (natural and basic heat only – no beryllium treatment).  None of this is currently listed but we invite you to contact us directly if you are interested.

cheers for now from Aussie Sapphire


New England Sapphire

November 4, 2006

Have just loaded up a new article we have written about Sapphire and Ruby in NSW, Australia with particular reference to New England sapphire.  The article contains a number of photos so take a look.  We welcome your feedback so feel free to leave a comment.

cheers for now from Aussie Sapphire


New Sapphire Rough Available

October 25, 2006

Have been pretty busy lately working a new patch of the mine and have been producing some very nice rough.  Have managed to find a little time to list just a small selection of this including a couple of very special pieces that we have had put away for a while now.

We can now safely say we have something to suit everyone with affordable pieces costing less than $100 per piece up to some very large pieces which suit the investor or collector.  The largest piece of sapphire rough we have listed currently is a whopping 47.5 carat blue which is impressive in every way – we dont mind window shoppers so make sure you take a look at this rare beauty.

We have also just received back our latest batch of cutting – some excellent cut sapphires here in a range of sizes, shapes and colours including some very nice parti-coloured sapphire (greens, bicolor and yellow).  We were able to cut about a third of this batch fully natural – ie. untreated in any way so if you are looking for unheated sapphire, we hope to have something suitable for you.

new_rounds.JPGJust a quick photo here to whet your appetite (click to see full size): this is just a batch of mixed size rounds tipped out on our grading table.  About 660 carats here and plenty of sorting into sizes and grading for colour to be done but at a rough glance, we can see some great partis and yellows with the majority of the parcel being our typical Reddestone blues. 

 cheers for now from Aussie Sapphire