Thursday, 28 October 2021

Gem Butterflies

The incredible colours of rhodochrosite, haüyne, sphene, yogo sapphires, tanzanites, hiddenite, garnets and benitoites at the Los Angeles County Natural History Museum, in the Butterfly Broach Collection.

http://gringa-gem-news.blogspot.ca/2012_06_01_archive.html


This brooch is almost entirely set with benitoite, the California state gemstone.
A barium-titanium silicate mineral (BaTiSi3O9), benitoite is a rare mineral, crystals large enough to be cut into gemstones are found only in one location: the Dallas gem mine in San Benito County, California. An unusual geologic setting of hydrothermal veins between glaucophane schist and serpentinite created this rare mineral. Benitoite is known for its high dispersion and its vivid blue fluorescence in UV light.
Orange spessartine garnets from the Little Three mine in Ramona, California highlight this brooch, along with colorless diamonds and green tsavorite garnets from Kenya.
The multi-colored sparkle of this butterfly emanates from its green titanites (“sphene”) from Madagascar. The "fire" of titanite derives from its high dispersion and refraction. Titanite (CaTiSiO5) is a fairly common accessory mineral in igneous and metamorphic rocks, but is seldom found in size and quality suitable for gems.


This butterfly brooch brings together titanites in three different colors: green from Madagascar, brown and yellow from Pakistan.

A 13.51ct rhodocrosite (MnCO3). This mineral is very rare in jewelry. Apatite and opal cover the wings, the eyes are green chromium-rich titanite (sphene).
Pink and red spinels from Vietnam highlight this butterfly brooch. Red spinel (MgAl2O4) has long been used as an affordable alternative to ruby. Some famous historical rubies are actually red spinels. Spinel is now very popular in its own right. The eyes of the butterfly are blue jeremejevites (Al6(BO3)5(F,OH)3) from Namibia.
A 10.01-ct green hiddenite is the central piece of the brooch. Hiddenite is a green variety of the mineral spodumene (LiAl(SiO3)2) in which the color is caused by small amounts of the element. chromium. Hiddenite from North Carolina is found associated with emerald, the green variety of beryl, which also owes its color to chromium. The body of this butterfly is the world's largest faceted hiddenite.
This butterfly brooch is set with blue sapphires from Yogo Gulch, Montana. Sapphire senso stricto is the blue variety of corundum (Al2O3).

Wallace Chan

Eli Frei

Van Cleef & Arpels

Diamond and Gemstone Butterfly Brooch in 18K and Platinum.

Victorian Gemstone Butterfly Brooch

A pearl, diamond and cabochon emerald butterfly brooch by Buccellati.

A carved boulder opal butterfly brooch with diamonds and sapphires.

Cindy Chao

Fire Opal Butterfly brooch by Shaun Leane.

Anna Hu’s pair of high jewellery earrings.


Van Cleef & Arpels Papillons Butterfly blue and diamond brooch

Van Cleef & Arpels

Akiva Gil

Graff multi-cut diamond butterfly brooch 119.99 carats

Wallace Chans " Whimsical Blue" Butterfly

Monday, 25 October 2021

Blue Garnets

Garnets are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different species are pyrope, almandine, spessartine, grossular, uvarovite and andradite.

Garnet is available in a plethora of colours and is found around the world. Rarest and most valuable of all are blue pyrope–spessartine garnets. They were discovered in 1998 in Bekily, Southern Madagascar. They are actually colour change garnets, appearing blue under fluorescent light changing to reddish-purple under incandescent light. The color change is pronounced and these rare garnets have become highly sought after by collectors.
Color change garnets are due in part to varying concentrations of vanadium and chromium. The blue-green to purple color change garnets have relatively high concentrations of vanadium and low concentrations of chromium.

Very fine, gem quality blue garnets over 10 carats are scarce and valuable.

Saturday, 23 October 2021

Graff's Pigeon Blood Ruby - $8.6M

In 2014 the 8.62-carat cushion-shaped 'Graff Ruby' ring from the collection of Dimitri Mavrommatis soared beyond estimates and set a then world auction record for a ruby at $8,600,410, as well as a record price per carat for a ruby at $997,727.

Another highlight of the evening was a natural pearl and diamond necklace that was likely once the property of Joséphine de Beauharnais, the first wife of Napoleon Bonaparte. Comprising 111 pearls, the necklace sold for $3,426,669, well above the pre-sale estimate of $800,000-$1,400,000.
In addition to the Graff Ruby, the collection included a rare 27.54-carat step-cut Kashmir sapphire with a velvety blue color that sold for $5,984,474, a world auction record for a Kashmir sapphire. It had an estimate of $3m to $6m.
A pair of sapphire, ruby and diamond earrings, by JAR. Each of circular form, pavé-set with circular-cut sapphires of various hues ranging from light pink to purplish blue, surmounted with a cage set cushion-shaped stone, one a diamond weighing 3.06 carats, the other a ruby weighing 4.89 carats. Estimate 385,000 — 670,000 CHF. Lot sold 557,000 CHF.

Tuesday, 19 October 2021

Top Investment Gemstones

Investing in gemstones is not for everybody. Rare gems do have an excellent record of increasing in value over time. When other assets are declining and currency is losing value, gemstones tend to be a reliable store of value. They are compact, portable and private.
While gemstones are not as liquid as other investments, a high quality gem will retain its value. In general the global demand for fine gemstones exceeds supply, and gemstone prices mainly move upward over time.
Fine ruby is the rarest of all colored gems, and Burmese ruby has long been the premier investment gem. Fine unheated Burmese rubies in larger sizes draw large prices. Vivid red, known as pigeon's blood, is the most valuable. Rubies tend to have inclusions, so intensity of color is more important than clarity.

Burma rubies are by far the most valuable, but fine unheated rubies from other locations such as Madagascar, Mozambique and Tanzania are increasing in value.
Blue sapphire is the second most popular colored stone for investment. The rarest and most valuable sapphires are from Kashmir, but no new material has been mined there in more than a century. Next most valuable is Burma sapphire, followed by stones from Ceylon and Madagascar. Fancy color sapphires, yellow, pink and padpardascha are popular.
The emerald market has seen turmoil as a result of treatments with artificial resins, but fine, untreated emeralds continue to be reliable investments. Colombian emeralds, especially in larger sizes, continue to be the most valuable, followed by the best Brazilian emeralds. High quality emeralds are also being mined in Zambia.

Investment grade emeralds must be untreated.
Spinel is a relative newcomer as an investment gem. The most valuable spinel colors are red, hot pink and flame orange. Red Burmese spinels and the neon pink-red spinels from Mahenge, Tanzania have the best investment potential.

Spinel is completely untreated and prices on fine pieces have risen significantly in the last 5 years.
Tsavorite Garnet is a rare gem that has begun to challenge emerald as the finest of the green gemstones. Unlike emerald, tsavorite is always untreated. It has more brilliance than emerald due to its higher refractive index.

Tsavorite garnets over 2 carats are very rare, and fine stones over 4 carats are exceptionally rare. Colors range from mint green to a deep chrome green.
Spessartite Garnet is a bright orange garnet colored by manganese. The finest examples, referred to as Mandarin Garnet, are a pure orange that is one of the most vivid colors in the gemstone world.

Pure orange specimens are very rare. They come mainly from Nigeria and Namibia. Large, clean stones are valuable and display a remarkable brilliance.
Alexandrite is a rare chrysoberyl that is popular with collectors for its striking color change and excellent hardness (8.5 on the Mohs scale). Alexandrite was first discovered in Russia. High quality alexandrite comes from Brazil, with medium grade material from Tanzania.
Fine translucent emerald-green jadeite is known as Imperial Jade. This rare gem is found mainly in Burma (Myanmar) and is coveted by collectors around the world, especially in Asia.

Type A jadeite is untreated natural Burmese jadeite where the color is 100% natural. Only certified jadeite of this quality is deemed worthy of investment.
The rarest topaz known is called Imperial topaz and its sole source is the Ouro Prêto area in Minas Gerais, Brazil. This topaz is golden-orange to orange to pink, pinkish-red or violet in color.

The color must be completely natural, with no enhancement by heat or other methods. Stones with a hint of pink or red are the most valuable, with a pure red natural topaz counting as extraordinary.
Paraiba tourmaline is a rare copper-bearing variety of tourmaline with a distinctive neon-like glow. It was first discovered in the Brazilian state of Paraiba in 1989. Since then small deposits have been found in Nigeria and Mozambique.

The Brazilian paraiba remains the most valuable, but color and clarity are more important than origin for these rare gems. Clean paraiba tourmalines with vivid color are the most valuable.
When buying gemstones for investment, it is critical to buy top grade gems. Low quality commercial grade stones are worthless to the investor. Fine gemstones are distinguished by vivid, intense color, outstanding clarity, and excellent cut. Buy the absolute best and ignore the rest, it is money invested, not spent.