Ruby Stone

A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires. The ruby is considered one of the four precious stones, together with the sapphire, the emerald and the diamond. 

Prices of rubies are primarily determined by color. The brightest and most valuable "red" called blood-red, commands a large premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. Cut and carat (weight) are also an important factor in determining the price.

Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only moissanite and diamond are harder, with diamond having a Mohs hardness of 10.0 and moissonite falling somewhere in between corundum (ruby) and diamond in hardness. Ruby is α-alumina (the most stable form of Al₂O₃) in which a small fraction of the aluminium³⁺ ions are replaced by chromium³⁺ ions. Each Cr³⁺ is surrounded octahedrally by six O^2- ions. This crystallographic arrangement strongly affects each Cr³⁺, resulting in light absorption in the yellow-green region of the spectrum and thus in the red color of the gem. When yellow-green light is absorbed by Cr³⁺, it is re-emitted as red luminescence.^[2] This red emission adds to the red color perceived by the subtraction of green and violet light from white light, and adds luster to the gem's appearance. When the optical arrangement is such that the emission is stimulated by 694-nanometer photons reflecting back and forth between two mirrors, the emission grows strongly in intensity. This effect was used by Theodore Maiman in 1960 to make the first successful laser, based on ruby.

All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as "silk". Gemologists use these needle inclusions found in natural rubies to distinguish them from synthetics, simulants, or substitutes. Usually the rough stone is heated before cutting. Almost all rubies today are treated in some form, with heat treatment being the most common practice. However, rubies that are completely untreated but still of excellent quality command a large premium.

Some rubies show a three-point or six-point asterism or "star". These rubies are cut into cabochons to display the effect properly. Asterisms are best visible with a single-light source, and move across the stone as the light moves or the stone is rotated. Such effects occur when light is reflected off the "silk" (the structurally oriented rutile needle inclusions) in a certain way. This is one example where inclusions increase the value of a gemstone. Furthermore, rubies can show color changes—though this occurs very rarely—as well as chatoyancy or the "cat's eye" effect.

Factors Affecting Values

Diamonds are graded using criteria that have become known as the four Cs, namely color, cut, clarity and carat weight. Similarly natural rubies can be evaluated using the four Cs together with their size and geographic origin.

Color: In the evaluation of colored gemstones, color is the most important factor. Color divides into three components; hue, saturation and tone. Hue refers to "color" as we normally use the term. Transparent gemstones occur in the following primary hues: red, orange, yellow, green, blue, violet. These are known as pure spectral hues.^[11] In nature there are rarely pure hues so when speaking of the hue of a gemstone we speak of primary and secondary and sometimes tertiary hues. In ruby the primary hue must be red. All other hues of the gem species corundum are called sapphire. Ruby may exhibit a range of secondary hues. Orange, purple, violet and pink are possible.

The finest ruby is best described as being a vivid medium-dark toned red. Secondary hues add an additional complication. Pink, orange, and purple are the normal secondary hues in ruby. Of the three, purple is preferred because, firstly, the purple reinforces the red making it appear richer.^[11] Secondly, purple occupies a position on the color wheel halfway between red and blue. In Burma where the term pigeon blood originated, rubies are set in pure gold. Pure gold is itself a highly saturated yellow. Set a purplish-red ruby in yellow and the yellow neutralizes its complement blue leaving the stone appearing to be pure red in the setting. (wikipedia.org)

Marty Natalegawa: Mandela Pejuang Menumpas Ketidak Adilan

Meninggalnya mantan Presiden Afrika Selatan Nelson Mandela tak hanya membawa duka mendalam bagi masyarakat Afrika Selatan, tetapi masyarakat dunia. Menteri Luar Negeri RI Marty Natalegawa selain menyampaikan belasungkawa juga turut berduka. Menurut Marty, Mandela adalah tokoh dunia yang berjuang menentang ketidakadilan.

"Nelson Mandela adalah seorang tokoh yang menjadi inspirasi di seluruh pelosok dunia, khususnya negara berkembang, untuk menentang rasisme, kolonialisme, dan berbagai bentuk ketidak adilan lainnya," ujar Marty dalam siaran pers melalui pesan elektroniknya, Jumat (6/12/2013).

Karena itu, Marty dan seluruh masyarakat dunia tentu sangat merasa kehilangan sosok Mandela. Selama ini belum ada sosok yang secara teguh dan prinsipal menentang kebijakan politik apartheid. "Kita semua merasakan duka yang sangat mendalam atas wafatnya seorang tokoh dan pejuang yang secara teguh dan prinsipil menentang kebijakan apartheid yang keji," ujar Marty.

Mandela meninggal dunia pada usia 95 tahun setelah menjalani perawatan karena infeksi paru-paru selama 3 bulan belakangan. Dalam pernyataan yang disiarkan stasiun TV nasional Afrika Selatan, Presiden Jacob Zuma mengatakan Mandela 'pergi dengan damai'.

"Bangsa kita kehilangan putra terbaiknya," kata Zuma seperti yang dilansir BBC, Jumat 6 Desember.

Sejak keluar dari rumah sakit, kantor kepresidenan Afrika Selatan berulang kali menyebutkan kondisi tokoh peraih Nobel Perdamaian tahun 1993 dan terpilih sebagai presiden kulit hitam pertama Afrika Selatan tahun 1994 ini dalam keadaan kritis namun stabil.

Pink Star Diamond Has Sold For US$. 83 Million

A diamond known as the Pink Star has sold for $83m (£52m) at auction in Geneva - a record price for a gemstone. The diamond measures 2.69cm by 2.06cm (1.06 inches by 0.81 inches) and is set on a ring.

The Pink Star was sold to Isaac Wolf, a well known New York diamond cutter who has renamed it the Pink Dream.

The winning bid surpasses the $46.2m paid for the Graff Pink diamond three years ago, which was half the size of the Pink Star.

The $83m includes Sotheby's commission.

The winning bid was for 68m Swiss francs ($74m) and reports say there was a long silence between that offer and the previous telephone bid of 67m Swiss francs.

"Ladies and gentlemen, 68 million is the world record bid for a diamond ever bid and it's right here," Sotheby's David Bennett said as he brought down the hammer.

Sotheby's played the theme tune from the "Pink Panther" movie after the winning bid was confirmed.

Origins

According to the auctioneer, the Pink Star was mined by De Beers in Africa in 1999, but it did not say which country.

"It's really extraordinarily rare," said Mr Bennett.

"Very, very few of these stones have ever appeared at auction."

It took two years to cut and polish the diamond, which was 132.5 carat in its rough state.

In its finished condition the Pink Star is 59.60 carat, more than double the size of the next biggest diamond in its class.

A carat is a weight measurement used for gemstones and is 0.2g (0.00705 ounces).

Sotheby's has sold almost $200m worth of jewellery in its current auction, a record for a single auction according to the company. (BBC)

Giant Pink Diamond Auctioned For US$. 83 Million

How To Check If Your Diamond Is A Fake

Diamond Care

Since your diamond is a valuable investment, you’ll want to take proper care of it. This section contains some basic tips to help keep your diamond looking its best.

Diamond Care Do’s

Diamonds must be kept clean and stored carefully when they are not being worn. Here are some guidelines to help keep your diamond in top condition:

If you notice loose stone settings or any other noticeable damages to your jewelry, do not continue to wear the jewelry. Take it to a trusted, professional jeweler who can make an assessment and repair the jewelry. We recommend that you have a jeweler check the setting in your diamond ring, stud earrings or solitaire pendants (while you watch) once a year.

Blue Sapphire

Sapphire The blue sister of ruby. Ruby and sapphire are the same material, the mineral corundum, and the second hardest gemstone after diamond. Red corundum is known as ruby, while all other colors are referred to as sapphire. While blue is the classic sapphire color, sapphire is actually found in a wide range of colors.

 

Sapphire colors
Blue is the most famous of the sapphire colors. The prized Kashmir and Burmese sapphires have a deep blue that is intense and velvety. These sapphires are not often seen on the market today. Sri Lankan and Madagascar sapphires are the most common today, with a wide range of colors from light sky blue to dark blue. Other producers of blue sapphire are Australia, Tanzania, Thailand, Cambodia, and the USA (Montana).

Precious Stones: Almandine Garnet Origin

Almandine Garnet, sometimes referred to as almandite garnet, belongs to the very vast and popular mineral group of garnet. Almandine is the most common of all garnet varieties. Although there are very large amounts of almandine sourced from all over the world, only a small percentage of the stones mined are of gem quality. Most almandine stones are opaque and rough and are only able to be used for industrial purposes. Garnet stones are often used for sandblasting in the Industrial trade.

The word 'Garnet' is derived from the Latin word "granatus", which means grain, because many garnet deposits are small grains of red crystals in or on their host rock. The specific name of almandine originates from the name alabandicus which is named after a stone found in the small town of Alabanda, located in Caria, the second smallest province of Asia Minor. Almandine occurs in a range of reds from dark brownish to purplish red and is a very popular gem choice for jewelers due to the excellent hardness (7.5 on the Mohs scale) and brilliance resulting from its high refractive index. Almandine garnet is often cut en cabochon with convex faces, and these specimens are sometimes referred to as carbuncle. Carbuncle is an old term used to describe any type of red gemstone cabochon. Red gemstones cabochons have historically been used as friendship gems. Garnet is also January's birthstone.

 

Identifying Almandine Garnet

Almandine garnet in appearance can be difficult to distinguish between other garnet types, as well as other red stones. Almandine garnet will typically have darker tones compared to other red gems, but top quality specimens do have red colors similar to that of ruby. A strong neodymium magnet will be able help distinguish garnet from other gemstones. Measuring a stone's magnetic susceptibility in collaboration with its refractive index can be used to distinguish specific garnet species and varieties, and it can also determine the percentage of composition in hybrid variety garnets.

Almandine Garnet Origin and Gemstone Sources Back to Top
Almandine Garnet stones can be found in many origins and sources including Brazil, India, Madagascar, Sri Lanka and the United States. Smaller deposits exist in Austria and the Czech Republic. Almandine garnet star gemstones are found in India and the United States. Idaho is known to be a very large source for star garnet gems. Amandine found in Sri Lanka is sometimes referred to as Ceylon-Ruby.

Almandine Garnet Color

Almandine garnet colors can range from pure red, reddish orange, slightly purplish red to dark brownish red. The unique deep red color of almandine is a direct result from the presence of iron.

Almandine garnet with pure, deep red colors are the most desirable and valuable of almandine stones.

Almandine Garnet Clarity and Luster

Almandine garnet has a vitreous luster. Gem quality almandine garnet is translucent, but depending on the cut, some stones may appear to be more translucent to opaque. Most almandine garnet rough is opaque and not considered to be of gem quality. These specimens are typically used for various industrial uses.

Almandine Garnet Cut and Shape

There are abundant amounts of very large sized almandine garnet crystals, but because of their dark tones, only small to medium sized gems are faceted. When faceted, they are often cut slightly shallow to allow light to pass through them. Some garnet stones when cut en cabochon can display an asterism effect; these are referred to as Star Garnets. Almandine garnet can be found in a wide variety of shapes and cut styles including round, oval, pear, heart and trillion facet or cabochon stones.

Almandine Garnet Treatment

Like most garnets stones, Almandine Garnet is not treated or artificially enhanced in any way.

 

Diamond Auction

A jadeite and diamond ring

The translucent green oval cabochon jadeite, measuring approximately 15.70 x 8.2 x 5.30mm, between shield-shaped diamond shoulders, mounted in white gold, ring size J

Sold for HK$ 312,500 (IDR 452,317,006) inc. premium 

 

 

 

 

 

 

Footnotes

• Accompanied by a GIA report stating that the jadeite jade is of natural colour. Certificate number 4252287, dated 12 March 1993.
  
  The jade cabochon has been remounted since this report was issued.

An art deco emerald and diamond bracelet, circa 1925

The articulated tapering strap composed of two rows of square and rectangular-cut emeralds in calibré settings, connected at intervals by seven pierced vertical rows of French-cut diamonds, each with a larger central diamond, millegrain detail throughout, mounted in platinum and gold, emeralds approximately 40.00 carats total, length 17.7cm, fitted brown leather case by S.J. Phillips, 113 New Bond Street, London

Estimate:

HK$ 775,000 - 1.16 million
IDR 1.1 billion - 1.7 billion
£63,000 - 95,000

Footnotes

• Accompanied by an SSEF report stating that at least 80% of the 50 emeralds are of Colombian origin with moderate clarity enhancement. Certificate number 36183, dated 19 September 2000.

A magnificent ruby and diamond strap bracelet, by Van Cleef & Arpels, 1936

Designed as a highly articulated mesh of oval-cut rubies interspersed with single baguette-cut diamonds, connected by pairs of tapered baguette-cut diamond scrolling ribbon motifs, to an integral clasp, mounted in platinum, unsigned but recorded in the archives of Van Cleef & Arpels, length 18.0cm

Sold for HK$ 3,620,000 (IDR 5,239,640,201) inc. premium 

 

 

 

 

Footnotes

• PROVENANCE
  'The Magnificent Jewels of Mme Hélène Beaumont', Sotheby's Geneva, May 18, 1994, Lot 522.
  
  Although the bracelet is unmarked, it is recorded in the Van Cleef & Arpels' archive as number 44724 and as being composed of 107.25 carats of rubies and 16.70 carats of diamonds. Van Cleef & Arpels has confirmed that it left the workshop of Rubel Frères on 10 April 1936 and it was purchased on 14 May 1936. The lack of signature, number and Rubel Frères' maker's mark is probably due to the bracelet being altered at some point before it was sold at the Sotheby's auction in 1994.

 

An important emerald and diamond necklace/choker/bracelet combination, by Van Cleef & Arpels, 1960-1961

The collar necklace designed as a series of twenty-two graduating clusters, each set to the centre with a step-cut emerald within a frame of brilliant-cut diamonds, the necklace detaches into four parts and may be worn as a shorter choker and a pair of bracelets, mounted in platinum and 18 carat gold, emeralds weigh 47.04 carats total, diamonds weigh 70.60 carats total, numbered 92116, French workshop marks, French assay marks length 42.0cm

Sold for HK$ 9,620,000 (IDR 13,924,126,722) inc. premium 

 

 

Footnotes

• Accompanied by a certificate from American Gemological Laboratories (AGL) stating the natural emeralds are of Colombian origin with faint to moderate clarity enhancement by oil. Report number CS32505, dated 12 January 1999.
  
  
  LITERATURE
  Christie's, 'Review of the Season 1975', edited by John Herbert, London, page 175, where the necklace is noted as having sold at auction in Geneva for CHF 1,000,000.
  
  Raulet, Sylvie, 'Van Cleef & Arpels', Rizzoli New York, 1987, pages 78 and 79 where is it described and illustrated.

An exceptional sapphire and diamond ring, by Van Cleef & Arpels, circa 1969

The cut-cornered rectangular-cut sapphire, weighing 43.16 carats, between pear-shaped diamond shoulders, weighing 1.60 carats total, mounted in platinum, signed Van Cleef & Arpels, numbered 112235 SA, French maker's marks, French assay mark ring size P

Sold for HK$ 12,084,000 (IDR 17,490,555,854) inc. premium

 

 

 

 

 

Footnotes

• Accompanied by an AGL report stating that the sapphire is of Ceylon (Sri Lankan) origin with no evidence of heat treatment or clarity enhancement. Certificate number CS36522, dated 2 October 2003.
  
  
  LITERATURE
  Raulet, Sylvie, 'Van Cleef & Arpels', Rizzoli New York, 1986, page 80:
  "In 1969, in Colombo, Jacques Arpels acquired an emerald-cut Ceylon sapphire of 43.16 carats, a quite remarkable, perfectly crystalline, flawless stone. It was mounted as a ring, flanked by two pear-shaped diamonds, a marvel in the House's collection".
  
  Exhibition catalogue, 'Legends of Van Cleef & Arpels, The Galliera Exhibition', Paris, 1992, no 89.