Tag Archives: Siberian amethyst

The Making of a Masterpiece V

An exceptional 32 carat Siberian amethyst custom cut by John Dyer

An exceptional 32 carat Siberian amethyst custom cut by John Dyer

by Richard W. Wise, G.G.

©2010

In the old days an apprentice goldsmith was required to submit a finished work, sort o final exam and thesis in metal to prove his skills and worthiness to hold the title of master goldsmith.  This work was known  as a masterpiece.

Per usual at R. W. Wise, a client’s purchase of a particularly beautiful gemstone began the journey.   The stone, a fairly large custom cut amethyst measuring 24 x 19mm, a tad large for a ring, practically begged to be made into a brooch.  In consultation with our client, it was decided that it would be a combination piece that would be wearable as both a pendant and a brooch.

The client is particularly drawn to designs from The Art Nouveau Period (1890-1910).  Le art nouveau, literally the new art, evolved from the Arts & Crafts Movement (1860-1880),  really a philosophy as much as a movement that put great emphasis on naturalistic design, hand craftsmanship and the use of honest materials.

A 18k gold, plique a jour pendant by Art Nouveau master Lucien Gautrait. R. W. Wise Collection. Photo: Jeff Scovil

A 18k gold, plique a jour pendant by Art Nouveau master Lucien Gautrait. R. W. Wise Collection. Photo: Jeff Scovil

Art Nouveau jewelers retained the design concept but pulled out the stops when it came to use of materials. Drawing inspiration from ancient Celtic and Gothic designs, jewelry of this period are executed with naturalistic, often fantastical females and floral designs featuring asymmetrical whiplash like filigree.   Art Nouveau designs are often quite intricate, made extensive use of enameling as well as exotic gemstones of all colors.

From Concept to Completion:

The Concept:

As with all custom design, the first step is the concept.  The client supplied us with pictures of period designs.  Master goldsmith Michael Corneau then reinterpreted the design ideas into a pendant/brooch that would frame the gemstone.

The finished sketch. The empty center is precisely the size of the gemstone. At the upper left the designer holds a narrow piece of shaped 18k gold wire the first section of the piece. Photo: Amy Judd

The finished sketch. The empty center is precisely the size of the gemstone. At the upper left the designer holds a narrow piece of shaped 18k gold wire the first section of the piece. Photo: Amy Judd

Execution:

Once the sketch is approved, we move on to execute the design.  In this case the construction involved a large number of individually shaped elements.

The following images illustrate the construction process:

A series of tiny shapes, cut out, filed and fitted, then laser welded.  Photo:  Amy Judd

A series of tiny shapes, cut out, filed and fitted, then laser welded. Photo: Amy Judd

Soldering the elements.  Photo:  Amy Judd

Soldering the elements. Photo: Amy Judd

Working with the flexible shaft tool, shaping and smoothing.  Photo:  Amy Judd

Working with the flexible shaft tool, shaping and smoothing. Photo: Amy Judd

The finished Piece:

18k Art Nouveau style brooch with 32 carat Deep Siberian amethyst.  Photo:  Robert Weldon

18k Art Nouveau style brooch with 32 carat Deep Siberian amethyst. Photo: Robert Weldon


Inside The Vault; The Diamond Fund, Part II

by Richard W. Wise

©2010

It is difficult to know where to start.  You enter The Diamond Fund through a vault-like door.  The room is simple, dark and unadorned.  The showcases are brightly lit.  Unlike the rest of the Armoury, the room is quiet, only two groups are allowed in at any one time.  The first case contains a pile of diamonds.  How else to describe it?  Included are some beautifully formed bi-pyramidal crystals—several a large as quail’s eggs!  I have as yet found no written reference which describes these stones and gives their history, but modern names such as the 342.50 carat “34th Communist Party Congress (actually found in Yakutia) and the 40.54 carat “Soyuz Apollo” suggest that they were sourced in the Siberian fields during the Soviet Era.

In Europe’s Royal Jewel Game; it was all about size:

After visiting the The Armoury, The Diamond Fund, The Hermitage and The Victoria and Albert (not bad for one trip, hey!) I am struck by how much quality standards in gemstones have changed over the centuries.  Obviously the stone in these collections were some of the finest in the world, but they are what we today would strongly fault for the quality of their cut as well as for the often substantial number of eye-visible inclusions.  It is important to note, however, that the testosterone fueled game as it was played by the royal houses of Europe was more about size than it was about quality.  Having the biggest sapphire trumped having a lot of smaller higher quality gems.    The point was, “mine is bigger than yours” and if the color was a little off or the cut was wonky, so what!

The Shah Diamond, so named because it was owned and signed by no less than three royal owners

The Shah Diamond, so named because it was owned and signed by no less than three of its first four royal owners

The Shah Diamond–Truly Expensive Graffiti:

The holdings include two historically important stones.  The first is  the 88.70 carat Shah Diamond, a Golconda stone from the famous  Indian deposits.   This diamond, hardly more than polished rough, has a history going back to 1544.  We know who owned the stone because each of the owners signed it.   The first inscription, perhaps the most expensive graffiti on earth, reads:  “Burzam-Nizam Shah the second, Year 1000” (1591).  Next it was owned by Akbar, the first emperor of the Mogul dynasty of India, and then by his grandson, the gem loving Shah Jehan who added his own inscription in 1644.  The final signature reads:  “The ruler kajar Fath Ali Shah Sultan” and was carved in 1824.      The stone, which appeared to me to be of high color, is described as “light yellowish brown” due to minute cracks in the crystal which contain iron oxide.  These cracks are quite invisible to the naked eye.  The stone is a natural octahedral crystal with polished faces.

The second diamond is the Orloff.  I was particularly keen to have an opportunity to see this great gem in person.  This stone was first described by the 17th Century adventurer Jean Baptiste Tavernier which many readers will recall is the protagonist in my newly published historical novel, The French Blue.  An expert observer, Tavernier was also a skillful artist; his rendering of this stone was first published in his Six Voyages (1678) and reproduced in the novel.  The stone is in the shape of a giant gum drop, faceted up the sides and across the top.  Tavernier describes it as being of the finest water.  Golconda diamonds are usually type IIa stones, contain no measurable Nitrogen, and do not fluoresce to ultra violet light.  Russian experts have noted “a barely noticeable bluish green tinge”, an ill understood phenomenon that is sometimes seen and described in Golconda diamonds such as The Regent, despite their lack of fluorescence.  Diamonds of this type are highly crystalline and are often described as “whiter than white” and bring substantial premiums at auction.

The Orlof, probably the same diamond called The Great Moghul and described by Jean Baptiste Tavernier in The French Blue.

The Orloff, probably the same diamond called The Great Moghul, and described by Jean Baptiste Tavernier in The French Blue.

Another beautiful stone, a tourmaline originally thought to be a ruby and weighing 260.86 carats is set with a green enameled foliate cap.  The stone was set in the rough and it resembles the shape and color of a strawberry.  It has numerous visible inclusions that add to the fruit like look.  It was originally owned by Rudolph II of Bohemia and described by De Boot and called at that time, “Caesar’s Ruby.”  It was presented to Catherine the Great in 1777.  De Boot valued it at 60,000 ducats.

Update–Siberian Amethyst:

Arrived London on the 21st.  Spent a good part of yesterday viewing the famous Victoria & Albert Museum’s jewelry collection.  Included is a platinum necklace with a suite of several very large (200 carat plus) amethysts given by Czar Alexander I to Frances Anne, wife of the 3rd Marquess of Londonderry.  The suite is of Siberian amethyst.  Given the provenance, you would expect these stones to be the finest of their kind.  While, fine enough, measuring perhaps 8.4 on a 1-10 scale, they do not stand up to the finest Zambian and Brazilian material and seem to lack the requisite red flash.

Siberian Amethyst, Debunking Another Myth of the Gem Trade.

by Richard W. Wise, G.G.

© 2010

ZambianAmethyst

A lovely example of Zambian amethyst, note the red flashes at 6 and 12:00 oclock. The alternating zones of purple and blue deliver a particularly velvety color

Quartz is as common as dirt.   At 12% it is the most abundant mineral in the earth’s crust and the primary component of ordinary dust.   Quartz is extremely stable and unlike other mineral components of the earth’s upper layer does not easily break down.

Amethyst is purple quartz, but despite the relative abundance of the mineral, exceptional fine rich purple amethyst, commonly called Siberian or deep Siberian color is extremely rare.  In Medieval times, there were two distinct varieties of gemstones bore the name. t Oriental amethyst, was actually purple sapphire and Occidental amethyst, the quartz gem that bears the name today.  Amethyst has seesawed in value over the centuries, today the finest of the fine might command $100 per carat at a high end jewelry store, in 1652, Nicols declared it to be of equal value to a diamond of the same weight.

I am not sure where the term Siberian originated and exactly how it became associated with the finest color in amethyst.   The usual reason why a specific locality gives its name to the finest quality of a given gemstones, (Kashmir sapphire, Burma ruby and Paraiba tourmaline)  is because the region is known to produce a particularly fine quality.  This is not the case with “Siberian” amethyst.  The fact is that for the past two centuries, the finest amethyst has come from Ceylon and Brazil (Streeter 1879)

Siberian amethyst is found in the Ural Mountains, with deposits outside the town of Mursinsk near the city of Ekaterinburg.  Amethyst has been mined in this area since at least the 18th century and probably earlier.  Sampling amethyst from mines active in this area in the 1830s, Gustav Rose, geologist with the famous Humboldt expedition (1837-1842) makes the following comment.  “The Mursinsk amethyst at times is very dark violet-blue surpassing that from Ceylon but mostly it is pale violet-blue (purple) or spotted and striped (zoned).”   John Sinkankas, who edited Rose’s text, calls this a “refreshing reappraisal” of Siberian amethyst and points out that Rose apparently held amethyst from Ceylon in the highest regard.    In 1900, the great German gemologist Dr. Max Bauer make the identical point adding only Brazil as a source of the finest examples of amethyst.  It is important to note that both these celebrated experts were able to view samples from actual working mines.  Other writers (Farrington 1903) identify Siberia as a major source for amethyst in the U. S. but this is contradicted by Streeter, Kunz and G-H Herbert Smith, whose popular Gem-Stones was, perhaps the most popular general book on gemstones in the 20th Century went through 14 separate editions between 1913-1972.

Up until the 1990s the primary world source for amethyst  were the Brazilian mines at Pau d’Arco, Rio Grande do Sul and Marabá. (Epstein 1988).   Pau d’Arco located in the Brazilian state of Para was discovered in 1979 and was known to produce a rich sometimes over saturated purple, which often exhibited the much desired red flash in incandescent light.  The other two sources produced a lighter brighter hued gem.  This writer saw large parcels of amethyst, often hundreds of carats, from all these sources available for sale in the gem market at Teofilo Otoni during this period.

In  the 1950s a new location of exceptionally fine gem material was located in Zambia in a  15 x 30 km belt, trending northwest in the Mwakambiko hills of the Mapatizya area of Zambia.  This material, a medium dark royal purple has become famous for its dark blue zones which add a velvety “royal” quality to the face up color much as a bit of purple does in the higher qualities of sapphire.  If one deposit were to be identified as the acme of amethyst it would be this one.

I was first introduced to the rough material in 1990.  Much of it was being smuggled into Nairobi, Kenya.  I had a good chance to examine the rough at that time and purchased several kilos.  The rough was a uniform deep purple of 80-85% tone with deep blue zones running through it.  Cut into gems it faced up with rich velvety slightly bluish purple and in incandescent light, the diagnostic red flashes and occasionally almost blue flashes of scintillation that are the hallmark of  deep Siberian quality.   Mining activity continues in Zambia but the major strike of exceptional material was mined out in the mid 1990s and a few gems cut from old rough are occasionally seen in the market.