Sunday, 21 May 2017

Andalusite

Andalusite is an aluminum silicate closely related to both sillimanite and kyanite. All three minerals are polymorphs. They share the same chemical composition, but possess different crystal structures. Andalusite is a strikingly beautiful gem, but it is one of the lesser-known gem types in the trade.
Andalusite gemstones are found in very distinct combinations of colors, with a very pronounced level of pleochroism.

New-found appreciation for andalusite is greatly owed to its unmistakable and unique twist on play of color. For many years andalusite has primarily been a collector's stone, but it has recently gained attention from jewelry designers.

It is an ideal hardness, about 7.5 on the Mohs scale.

Friday, 19 May 2017

Demantoid Garnet

Demantoid is the green gemstone variety of andradite, a member of the garnet group. Andradite is a calcium-and iron-rich garnet with the formula Ca3Fe2(SiO4) with chromium the cause of the demantoid green color. Ferric iron is the cause of the yellow in the stone. Demantoid garnet was first discovered in 1886 and became a favorite of Russian royalty and designer Carl Fabergé, who incorporated them into his jewelry.
Russian mining of demantoid garnet was suspended after the Bolshevik Revolution in 1917, but resumed in the 1970s.
Demantoid gets its name from the Dutch words for “diamond-like.” The stone owes its impressive brilliance to two main factors: A high refractive index and a high dispersion. Demantoid’s dispersion rating is the highest of all gemstones, including diamond. Known for their brilliant green color and fiery dispersion, demantoid garnets are unique because their inclusions — usually seen as flaws in other gems — are considered highly coveted aesthetic attributes.
Demantoid garnet is mined in other parts of the world, including Iran, Namibia, Pakistan, Italy, Madagascar and Canada, but Russian demantoid sets the mark by which all the others are compared. Demantoid garnets are rarely found in sizes larger than 2 carats.

Bonhams’ Rare Jewels & Jadeite Auction

Among the leading items on sale is a pair of emerald and diamond earrings; emeralds weighing in at more than 10 carats are a rarity, so to get two of 10.91 and 10.26 carats in a pair partly explains the estimated HK$3.8-4.8 million price.

The pair of Namibian fancy coloured diamond and diamond earrings from Forevermark are estimated at $2.3-2.8 million. The earrings feature two asscher-cut fancy intense yellow diamonds, weighing 5.26 and 5.17 carats.
A ruby and diamond bracelet, with an estimate of $2.3-2.8 million, features 30 vivid red pigeon-blood cushion-shape examples from Myanmar with a combined weight of 30 carats.

A step-cut 10.06 carat ruby set in a tsavorite garnet and diamond ring comes from Kenya. Set within a surround of pavé-set circular-cut tsavorite garnets and diamonds, it is estimated $1.5 million and $2 million.

Australian Black Opal and Diamond Pendant Necklace. It is estimated at US$43,000-54,000.

Padparadscha sapphire weighing 10.27 carats. It is estimated at US$80,000 - 86,000.

Cabochon emerald of 24.49 carats, est US$150,000-210,000.

Necklace composed of nine jadeite cabochons accented by pear and brilliant-cut diamonds. The suite has a pre-sale estimate of US$190,000-260,000

Emerald, Ruby and Diamond Necklace, Brooch and Earring Suite circa 1965. 27.20 carats of diamonds, approximately 36 carats of emeralds and approximately 105 carats of Burmese rubies. It has a pre-sale estimate of US$120,000-150,000

Thursday, 18 May 2017

Bejeweled Birds

The Peacock Brooch by London-based Graff boasts 1,305 diamonds weighing a total of 120.81 carats.

At the center is a 20.02-carat fancy deep blue pear-shape diamond, one of the rarest blue diamonds in the world. Adorning the tail feathers is an array of white, pink, yellow, orange, green and blue diamonds in various sizes and shapes. The tip of each feather is set with a cluster of white diamonds.
The Peacock Brooch made its first public appearance last year and can be yours for about $ 100m.

The historic and iconic “Walska Briolette Diamond” Brooch created by Van Cleef & Arpels in 1971. The Fancy Vivid Yellow antique briolette diamond weighs 96.62 carats. $10.5 million




Coral, emerald, diamond and onyx parrot brooch, Van Cleef & Arpels, circa 1990

'Bird of Paradise' brooch, Van Cleef & Arpels,

Lovebirds clip, 1946. Van Cleef & Arpels

Fabergé Visionnaire collection

Peter Carl Fabergé designed and produced hundreds of precious objects. Peter Carl Fabergé's vision: to create precious and original objects that surprise and delight. The Fabergé Visionnaire collection is a modern interpretation of this avant-garde mindset applied to fine watchmaking for men.
The movements for the Visionnaire timepieces were exclusively developed for Fabergé; APRP developed the movement for Visionnaire I, and Agenhor Manufacture equipped the Visionnaire DTZ and Visionnaire Chronograph. Visionnaire 1, with a movement by APRP price: about $250,000.