November 2016

/

Topaz in matrix (Photo GIA)

The Colorful World of Topaz

I have always thought it was a shame that the general public has been forced into the misconception that topaz is merely and inexpensive blue gem. Incidentally the blue color is hardly ever natural: It’s almost always caused by treatment. Topaz has a far broader and more colorful story to tell gemstone lovers. 

Topaz is allochromatic. This means that the color you see is caused by an elemental impurity or defect in its crystal structure rather than by an element of its basic chemical composition. For example, the presence of the element chromium causes natural pink, red, and violet-to-purple colors in topaz. Imperfections at the atomic level in topaz crystal structure can cause yellow, brown, and blue color. Brown is a common topaz color, and the gem is sometimes mistakenly called “smoky quartz.”

The 97.45-carat Blaze Imperial Topaz is in the collection of the Field Museum of Natural History. - (Photo: "Gems and Gemstones: Timeless Natural Beauty of the Mineral World" by Grande & Augustyn, U of Chicago Press.)

Topaz actually has an exceptionally wide color range that, besides brown, includes various tones and saturations of blue, green, yellow, orange, red, pink, and purple. Colorless topaz is plentiful, and (as was mentioned earlier) is often treated to give it a blue color.

The color varieties are often identified simply by hue name—blue topaz, pink topaz, and so forth—but there are also a couple of special trade names. Imperial topaz is a medium reddish orange to orange-red. This is one of the gem’s most expensive colors. Sherry topaz—named after the sherry wine—is a yellowish brown or brownish yellow to orange. You may hear stones in this color range are referred to as "precious topaz". This term is used to distinguish them from less expensive citrine (yellow quartz) and smoky quartz.

 

Topaz crystals are typically elongated, with grooves parallel to their lengths. For this reason, they're commonly cut into long oval or pear shapes. These crystals show orange, pink, and brown colors. - Eric Welch/GIA

What is Imperial Topaz?

Red is one of the most prized and rare topaz colors. Red represents less than one-half of 1 percent of facet-grade material found. The color known in the gem the trade as "imperial topaz" is even more highly prized and rare. They color is a bit elusive and subjective; however, many dealers insist that a stone must show a reddish pleochroic color to be called imperial topaz. The reddish pleochroic color often appears at the ends of fashioned gems—like pears and ovals—that have an otherwise yellow-to-orange bodycolor. This look is illustrated in the images below. 
The name for "imperial topaz" originated in nineteenth-century Russia. At the time, the Ural Mountains were topaz’s leading source, and the pink gemstone mined there was named to honor the Russian czar. Ownership of the gem was restricted to the royal family.

This untreated 45-carat imperial topaz displays an attractive reddish peach color. (Photo: Constantin Wild, Idar-Oberstein)

Spectacular prize-winning, orangy-red, flame-shaped Imperial Topaz gem. (Photo: Gem courtesy of John Dyer & Co.)

The Württemberg Pink Topaz Tiara

The Württemberg Pink Topaz Tiara features pink topaz stones 

This tiara is part of an extravagant parure which includes, the tiara, two bracelets, a pair of earrings, and a devant de corsage (large brooch).  The set features a series of large and small pink topaz stones, surrounded by diamonds, mounted in gold and silver.

Princess Marie in the Topaz Parure

All of the pieces feature diamonds and striking pink topaz. The topaz stones are believed to be sourced from Russia.
The parure is linked to Princess Marie of Waldeck and Pyrmont (1857-1882), who married Prince William of Württemberg (later King William II) in 1877. Marie died just five years later following complications during the birth of her third child, a stillborn daughter.  Her pink topaz jewels are no longer with the Württemberg family and were last associated with the Faerber Collection.

 

-Back to Top
Gemology 101

Allochromatic: When color is caused by impurity elements or defects in its crystal structure rather than by an element of its basic chemical composition.
Idiochromatic: An idiochromatic gem is one where the color is not due to impurities, but where the coloring element is an essential part of its chemical formula. An example of an idiochromatic gemstone is peridot, because iron is part of its makeup; no iron, no peridot. 
Pleochroic: Pleochroism is when a gemstone shows different colors in different crystal directions. 

Pleochroism in a tourmaline cut with the c-axis parallel to the table, as seen with the unaided eye through the side (left), crown (center), and end (right). (Photos: Wimon Manorotkul and Mia Dixon.)

What You Might Have Missed

October 2016

/
october

American Contra Luz Opal from Oregon, Sold by Bonhams Auction House

Opal

Opal is formed in dry areas such as Australia’s semi-desert “outback.” Seasonal rainwater drenches the dry regions and showers soak deep into ancient underground rock, carrying dissolved silica (a compound of silicon and oxygen) downward, forming deposits in cracks between rocks. During dry seasons much of the water evaporates, leaving the silica deposits underground in the cracks and fissures of sedimentary rock.

Depending on the conditions in which it formed, opal may be many colors. Precious opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these, black opals are considered the most rare while white and greens are the most common. 

As with their color opals vary in optical density from opaque to semitransparent, and there are two broad classes of opal: precious and common. Precious opal displays play-of-color while common opal does not.

Play-of-color occurs in precious opal is due to the way in which silica is arranged on a sub-microscopic level. Opal is made up of sub-microscopic silica spheres that arranged in a grid-like pattern (think of it like a box of ping pong balls). This arrangement causes light to bend (diffract). As the light bends it breaks apart into spectral colors (all the colors of the rainbow) producing an incredible display of color.  The color that can be seen varies with sphere size. According to GIA "spheres that are approximately 0.1 micron (one ten-millionth of a meter) in diameter produce violet. Spheres about 0.2 microns in size produce red.  Sizes in between produce the remaining rainbow colors".

-Back to Top

Opalized Fossils

OpaliZed freshwater mussell shells 110 million years old

What are Opalized Fossils?

Opal usually forms within fissures in rock layers, but opal can also form in other materials. If a cavity has formed because a bone, shell or pine-cone was buried in the sand or clay that later became the rock, opal may form in these cavities. 
One of the richest sources of opalized fossils is Lightning Ridge in northwestern New South Wales. These fascinating fossils transport us back in time approximately 110 million years! The fossils of dinosaurs, marine reptiles, fish, early mammals, mollusks, and plants give us a window into our planet's history. 

There are two kinds of opalized fossils:

Type 1. In this type the internal details are not preserved. The water and silica solution fills an empty space left by a shell, bone, etc. that has disintegrated away and then hardens to form an opalized cast of the original object. The opal inside doesn’t record any of the creature’s internal structure. Most opalized shell fossils are this type of ‘jelly mold’ fossils. 

Type 2. In this type internal details preserved: If the buried organic material hasn’t rotted away and a silica solution soaks into it, when the silica hardens it may form an opal replica of the internal structure of the object. This happens most often with with wood or bone.

OpaliZed theropod dinosaur tooth. Lightning Ridge, New South Wales.

OpaliZed Fossil Wood from Queensland Australia

The Virgin Rainbow

THOUGH superficially Belemnites resembled squid, they are distinct from modern squid for several reasons. they possess hard internal shells/skeletons composed of calcium carbonate and also lacked the pair of specialized hunting tentacles POSSESSED by modern cuttlefish and squid. belemnites instead hunted with ten arms covered in tiny hooks. (Artist's depiction of a belemnite school)

The Virgin Rainbow, it was discovered in the opal fields of Coober Pedy by opal miner John Dunstan in 2003. 
It's actually an opalized fossil, from an extinct cephalopod called belemnitida that existed during the Mesozoic era. During that time, much of South Australia was under a vast sea that was filled with prehistoric aquatic life. When these creatures died they sank to the bottom of the sea and were buried by sediment.

Over the millennia the sea eventually dried up and the land turned into a desert. The acidity levels in the shallow top layer of the sandstone increased causing the release of silica from weathering sandstone. Groundwater then carried it down to the layer of clay beneath, where bones and pockets left by disintegrated bones lay buried.

Further weathering lowered the acidity levels allowing the silica gel to harden into opals in the pockets and impressions left by decayed animal material to create a replica of the internal structure (see a description of opalized fossil types above).

The famous Australian opal fields of Coober Pedy are located in this prehistoric sea region. No other environment in the world is known to have undergone this same process, which very well may be why over 90 percent of the world's opals come from South Australia.

Artist rendering of a Plesiosaur next to the Addyman Plesiosaur

Opalized fossils in this region are not uncommon. The South Australian Museum is home to a spectacular (almost complete) opalised skeleton of a six-metre (20-foot) plesiosaur known as the Addyman Plesiosaur, although you have to look closely to see its opalescent sheen. This is not the case with the Virgin Rainbow.

The Virgin Rainbow opaliZed fossil of an extinct cephalopod called belemnitida that existed during the Mesozoic era.

"You'll never see another piece like that one, it's so special. That opal actually glows in the dark -- the darker the light, the more colour comes out of it, it's unbelievable," said Dunstan.

"I've done a lot of cutting and polishing [of opals], I've been doing it for 50 years, but when you compare it to the other pieces that claim to be the best ever, this one just killed it." 

The Virgin Rainbow is considered to be the finest opal ever unearthed and is worth more than $1 million. (In case you were wondering the Virgin Rainbow isn't even the most valuable opal in the world! A massive, 3.45-kilogram (7.6-pound) stone named the Olympic Australis opal, excavated in the Coober Pedy in 1956 gets that honor. In 2005, the Olympic Australis was valued at $2.5 million.)

Both the Addyman Plesiosaur and the Virgin Rainbow are currently on display among a dazzling collection of opals at the South Australia Museum in an exhibition, called "Opals". The exhibition began in September 25, 2015 and will run until February 14, 2016. 

"From jewellery to fossils to specimens embedded in rock, visitors will be treated to a spectacle of unmatched colour and beauty. This is an exhibition literally millions of years in the making because these opals were formed back when dinosaurs walked the earth and central Australia was an inland sea," - Museum Director Brian Oldman.

-Back to Top

Gemology 101

Aboriginal Origins of Opal

"The Path of Enlightenment" necklace contains 180 magnificent opals from Lightning Ridge, Australia, a famous opal producing area. - Courtesy Cody Opal

We Came From the Land  
This aboriginal story teaches how areas around the Flinders Ranges were created and the origins of opal. This is a Wirangu story from near Ceduna on the west coast of South Australia as told by M. Miller and W.J. Miller.

A long long time ago, a huge meteorite hurtled towards the earth from the northward sky, and smashed into the ground near Eucla. Because it was so big, a dent appeared in the crust of the earth and the meteorite bounced high into the air and out into the Great Australian Bight where it landed with an enormous sizzling splash. It was hot from its trip through space so it gave off a great deal of steam and gas as it sank through the waves. But this was no ordinary meteorite. It fact, it was the spirit Tjugud.
In the deep water near by, the spirit woman Tjuguda lay asleep. All the noise around her woke her up and she was very angry. She bellowed and the elements roared with her. The wind blew, the rain pelted from the sky and the dust swirled.
From the joining of the two spirits, the Tjugud and Tjuguda, a man was born, but he was no ordinary man, he was of enormous proportions. He rose from the deep water of the Bight to swim through the maze of limestone caves which run through the earth and into the sea. Then, he emerged from the ground through the cave of the Nullabor.
This was the birth of the Wirangu man, a coastal dweller. Wirangu walked towards the east, taking huge steps in keeping with the stature of the man. Each time he stepped, the ground shook and a dent appeared in the earth. These would later fill with water and are the rock holes which can still be seen today. You can clearly trace the journey of this man.
When he reached Coober Pedy, he was very hungry so he found some food and then lit a fire. The fire he built was so fierce it burned with an enormous amount of heat. A lot of water from the body of the man dropped into the ground and was captured by the stones which held a lot of water anyway. The beautiful colours from the raging fire went down into these stones, changing the water into a magnificent display of color. This is the colour of the opal and can be found in the stones still.

(Education Department of South Australia 1992: 32-33)

-Back to Top

What You Might Have Missed

Featured
CVD Synthetic Diamond Over 5 Carats Identified by GIA
CVD Synthetic Diamond Over 5 Carats Identified by GIA
Burmese Ruby, Jade Ban Officially Ended
Burmese Ruby, Jade Ban Officially Ended
Featured
Web of Light
Web of Light
Pantone's Fall 2016 Colors
Pantone's Fall 2016 Colors
Happy Birthday Tiffany & Co.
Happy Birthday Tiffany & Co.

July 2016

/
July2016

Features This Month:

Rough Ruby Crystal, Photo by GIA

Ruby 

The Graff Ruby sold  by Sothebys in 2014 for $8,600,410.00

The Graff Ruby sold  by Sothebys in 2014 for $8,600,410.00

The Sanskrit word for ruby is ratnaraj meaning "king of gemstones" and indeed the ruby has lived up to its name by being one of the most coveted gemstones in the world for the majority of recorded human history.
Ruby is the red colored variety of gem quality corundum (any other color of corundum is considered sapphire). Corundum is a crystalline form of aluminium oxide and one of the most durable minerals on earth.
The name ruby comes from the Latin word ruber meaning "red". The most valuable shade of red for rubies is what is called "pigeon-blood red", but rubies can be any shade of red (including purplish, orangy, or brownish). Star rubies may be almost pink in appearance.

“Sunrise Ruby,” untreated pigeon’s blood red-colored sold by Sotheby's

“Sunrise Ruby,” untreated pigeon’s blood red-colored sold by Sotheby's

Star Ruby and Diamond Ring by Cartier, sold by Sotheby's

Star Ruby and Diamond Ring by Cartier, sold by Sotheby's

Gemology 101: Asterism

Intersecting rutile needles (called “silk”) in sapphire. Photo by John I. Koivula. GIA (102014)

Intersecting rutile needles (called “silk”) in sapphire. Photo by John I. Koivula. GIA (102014)

Asterism is the name that was given to the phenomenon that causes gemstones to exhibit a star-like shape when cut into a cabochon. The optical phenomenon is displayed by some rubies, sapphires, and other gems (i.e. star garnet, star diopside, star spinel, etc.). The Star-effect or "asterism" is caused by the dense inclusions of tiny needlelike crystals of called rutile (also known as "silk"). The stars are caused by the light reflecting from needle-like inclusions of rutile which are aligned perpendicular to the rays of the star. Star gemstones are almost never transparent since rutile is always present in star gemstones.

Back to top

The Burmese Ruby Tiara

The Burmese Ruby Tiara worn by Queen Elizabeth

The Burmese Ruby Tiara worn by Queen Elizabeth

Queen Elizabeth II commissioned the tiara from Garrard in 1973. It was constructed using gems she already had on hand: 96 rubies which were a wedding present from the people of Burma and diamonds taken from another wedding present, the Nizam of Hyderabad Tiara. 
The tiara is designed to look like a wreath of roses. The roses are separated by rays of diamonds. The rubies are set in gold and the diamonds in silver.

Back to top

Not What it Seems: The Black Prince Ruby

The Black Prince's Ruby is one of the most famous members of the British Crown jewels, but despite its name, the stone is not a ruby.  The Black Prince's Ruby is actually a deep red un-faceted spinel. The stone, which has been in the possession of the British Royal Family since 1367, was named after Edward of Woodstock, Prince of Wales. It is one of the oldest of gems included in the Royal Collection of Crown Jewels and currently sits in the cross at the front of the Imperial State Crown, just above the Lesser Star of Africa (Cullinan II).

At an estimated weight of 170 carats and a length of almost 5 centimeters, the Black Prince's Ruby is the one of the world's largest uncut red spinel gemstones. The Black Prince's Ruby was polished into a bead-like shape which was drilled, strung and worn as a pendant and various other forms of jewelry prior to it being placed in the Imperial Crown. The drill hole has since been plugged with a smaller ruby.

Why was this spinel misidentified as a ruby? 

As with many other gemstones 'rubies' were historically a category of gemstones that would have included all red transparent gemstones. It wasn't until 1783 that spinel was differentiated from ruby. Spinel and ruby (corundum) can be distinguished based on its chemical properties and physical characteristics. 

Where did the Black Prince Ruby come from?

The Black Prince's Ruby was believed to have been mined in the 14th century somewhere from present-day Tajikistan, which was then known as Badakshan. The stone belonged to Prince Abu Sa'id of the Moorish Kingdom of Granada.  

During the mid 14th century the Moorish Kingdom of Granada was being attacked and placed once again under Castilian rule as a part of the Christian Reconquest of the Iberian peninsula. Abū Sa'īd's rule was confronted by that of Peter of Castile, also known as Don Pedro the Cruel. According to historical accounts, Abū Sa'īd wanted to surrender to Don Pedro. Don Pedro welcomed him to Seville. When Abū Sa'īd met with Don Pedro, Don Pedro had Abū Saī'd's servants killed and it is believed that he may have personally stabbed Sa'īd to death himself. It is said that when Don Pedro searched Sa'īd's corpse, the spinel was found and added to Don Pedro's possessions.

In 1366, Don Pedro's illegitimate brother, Henry of Trastámara, revolted against Don Pedro. Don Pedro made an alliance with the Black Prince, the son of Edward III of England in an attempt to thwart the revolt. After the revolt was successfully put down the Black Prince demanded the ruby in exchange for his aid. It is thought that Don Pedro was reluctantly obligated to turn the stone over and the Black Prince took the Ruby back to England.

The Ruby resurfaces again in 1415 when Henry V of England wore a gem-encrusted helmet that included the Black Prince's Ruby during his battle in France. In the Battle of Agincourt on October 25, 1415, the French Duke of Alençon struck Henry on the head with a battleaxe, and Henry nearly lost the helmet, along with his life. The battle was won by Henry's forces and the Black Prince's Ruby was saved. The gemstone was worn into battle once again by Richard III who wore the stone on his helmet at the Battle of Bosworth, where he died.

The Ruby as part of the British Crown Jewels

The 1512 inventory of Henry VIII's posessions mentions "a great balas ruby" set in the Tudor Crown. This is believed to be the Black Prince Ruby. It remained there until the time of Oliver Cromwell in the 17th century, when (excepting of the Coronation Chair and several other items) Cromwell had the principal symbols of the king's power disassembled and sold, while the gold was melted down and made into coins. The fate of the Black Prince's Ruby, during that time in England is not clear, but it came back into the monarchy's posession in 1660 when Charles II and the monarchy was restored. In 1838 Queen Victoria was crowned with a new Imperial State Crown made by Rundell and Bridge. The crown contained 3,093 gems, including the spinel at the front. This crown was remade in 1937 into the current, lighter, crown and a small plaque was placed on the reverse of the gemstone that commemorates the crown's history.

Back to top

Designer Spotlight

paul

This month's designer spotlight falls on Paul Morelli. 
History
The Fine Jewelry House of Paul Morelli was born from a culturally vibrant and artistic family tradition of theatre and handmade costumes. Founded in the early 20th century, in what was then the Philadelphia Theatre District, the Morellis became the premier company across the country for hand made, high quality and one-of-a-kind theatre garments.
In the late 70’s, Paul Morelli, followed his passion for art, intricate detail, fine jewels and metallurgy and transformed the family operation into a fine jewelry business. The Fine Jewelry House of Paul Morelli still operates in the same building where the Morelli family’s artistic roots took hold.
Today the House of Paul Morelli, under creative director Paul Morelli, designs and creates a unique and broad range of luxury fine jewelry from made-to-order, to timeless classics, to signature pieces reflecting current influences.
Under Paul’s discerning eye for detail, pieces continue to be brought to life through collaborative expertise in handcraftmanship and modern technology by teams of craftsmen at the House of Morelli. The Morelli family maintains control over the production of every piece of jewelry, ensuring that each piece meets the family's exacting standards and only then is certified with the Paul Morelli name.

What makes Paul Morelli's Jewelry Special?

SINGLE PEBBLE NECKLACE (SUMMER VERSION) A warm-toned strand of textured, diamond-encrusted and gemstone-set gold evokes pebbles awash on the seashore.

I don't think that it is a stretch to say that there is a lot of jewelry out there that, while gorgeous, looks like it's been cloned. When faced with this sea of identical imagery finding designers that are doing things differently is like breathing a breath of fresh air, Paul Morelli is one of these designers. The jewelry is bright and full of life, while also reflecting the care and the consideration for quality that goes in to every piece. Creativity and a passion for design will leave you wanting more. 

CASCADING LAGRANGE PEARL & DIAMOND NECKLACE
Inspired by Joseph-Louis Lagrange, an Italian Enlightenment Era mathematician and astronomer, who developed the mathematical equations used in pave diamond settings as well as the asymmetrical stone settings in this collection.

Back to top

As always, please feel free to send me any questions or comments via email. And, if you haven't already, be sure to join the daily conversation on Instagram, Twitter, Facebook or Tumblr! 

- Kathleen

Visit the Newsletter Archive for past editions