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Historical values 2005 - 2016

About Sapphire- History and Introduction

Color

Color Description; Occurrence

1 ct.

3 ct.

5 ct.

10 ct.

30 ct.

156 - dark Blue (heated)

Alternative name, occurrence category: Common

314.13

582.54

850.95

1,521.96

No data

155 - medium dark Blue; very slightly greyish (heated)

Alternative name, occurrence category: Common

485.66

900.62

1,315.58

2,352.98

No data

151 - medium Blue; strong (heated)

Alternative name, occurrence category: Common

1,086.96

2,015.70

2,944.44

5,266.29

No data

170 - medium bluish Violet; very slightly greyish (heated)

Alternative name, occurrence category: Common

822.06

1,524.46

2,226.85

3,982.84

No data

148 - medium light Blue; strong (heated)

Alternative name, occurrence category: Common

513.40

952.06

1,390.72

2,487.38

No data

133 - medium very strongly greenish Blue; strong (heated)

Alternative name, occurrence category: Common

416.89

773.10

1,129.30

2,019.82

No data

147 - light Blue; very slightly greyish (heated)

Alternative name, occurrence category: Common

317.26

588.34

859.41

1,537.11

No data

129 - light very strongly greenish Blue; very slightly greyish (heated)

Alternative name, occurrence category: Common

298.90

554.28

809.67

1,448.13

No data

181 - light bluish Purple; strong (heated)

Alternative name, occurrence category: Common

508.32

942.64

1,376.97

2,462.78

No data

176 - medium light Violet; strong (heated)

Alternative name, occurrence category: Common

678.28

1,257.82

1,837.37

3,286.22

No data

185 - medium bluish Purple; very slightly greyish (heated)

Alternative name, occurrence category: Common

945.92

1,754.14

2,562.36

4,582.92

No data

194 - medium Purple; very slightly greyish (heated)

Alternative name, occurrence category: Common

972.09

1,802.69

2,633.28

4,709.75

No data

208 - medium light strongly purplish Red; strond (heated)

Alternative name, occurrence category: Common

1,172.92

2,175.10

3,177.29

5,682.75

No data

014 - medium light orangey Red; strong (heated)

Alternative name, occurrence category: Common

888.48

1,647.63

2,406.78

4,304.65

No data

034 - medium Orange; strong (heated)

Alternative name, occurrence category: Common

317.65

589.06

860.47

1,539.00

No data

040 - medium orangey Yellow; strong (heated)

Alternative name, occurrence category: Common

298.50

553.56

808.61

1,446.24

No data

031 - light Orange; strong (heated)

Alternative name, occurrence category: Common

269.20

499.22

729.23

1,304.27

No data

044 - light Yellow; strong (heated)

Alternative name, occurrence category: Common

151.99

281.85

411.71

736.37

No data

073 - light slightly yellowish Green; strong (heated)

Alternative name, occurrence category: Common

149.25

276.78

404.31

723.12

No data

069 - medium yellowish Green; slightly greyish (heated)

Alternative name, occurrence category: Common

229.35

425.31

621.28

1,111.18

No data

077 - medium slightly yellowish Green; very slightly greyish (heated)

Alternative name, occurrence category: Common

311.79

578.19

844.60

1,510.60

No data

107 - medium bluish Green; very slightly greyish (heated)

Alternative name, occurrence category: Rare

393.84

730.35

1,066.86

1,908.13

No data

223 - colorless (heated)

Alternative name, occurrence category: Common

225.44

418.07

610.69

1,092.25

No data

155 - medium dark Blue; very slightly greyish (unheated)

Alternative name, occurrence category: Rare

1,391.72

2,580.85

3,769.99

6,742.82

No data

151 - medium Blue; strong (unheated)

Alternative name, occurrence category: Rare

1,908.63

3,539.44

5,170.24

9,247.24

No data

148 - medium light Blue; strong (unheated)

Alternative name, occurrence category: Rare

1,383.91

2,566.36

3,748.82

6,704.96

No data

158 - medium light violetish Blue; strong (unheated)

Alternative name, occurrence category: Rare

1,272.94

2,360.59

3,448.24

6,167.35

No data

129 - light very strongly greenish Blue; very slightly greyish (unheated)

Alternative name, occurrence category: Rare

904.50

1,677.34

2,450.17

4,382.26

No data

194 - medium Purple; very slightly greyish (unheated)

Alternative name, occurrence category: Rare

1,490.96

2,764.89

4,038.82

7,223.64

No data

188 - light Purple; strong (unheated)

Alternative name, occurrence category: Rare

1,083.45

2,009.18

2,934.92

5,249.25

No data

014 - medium light orangey Red; strong (unheated)

Alternative name, occurrence category: Rare

1,648.42

3,056.88

4,465.35

7,986.51

No data

013 - light orangey Red; strong (unheated)

Alternative name, occurrence category: Rare

930.29

1,725.16

2,520.03

4,507.20

No data

075 - medium light slightly yellowish Green; very slightly greyish (unheated)

Alternative name, occurrence category: Rare

542.31

1,005.68

1,469.05

2,627.47

No data

040 - medium orangey Yellow; strong (unheated)

Alternative name, occurrence category: Rare

569.27

1,055.67

1,542.07

2,758.08

No data

044 - light Yellow; strong (unheated)

Alternative name, occurrence category: Rare

344.61

639.05

933.50

1,669.61

No data

223 - colorless (unheated)

Alternative name, occurrence category: Rare

270.37

501.39

732.41

1,309.95

No data

About Sapphire - History and Introduction

Sapphire is a gem quality variety of the mineral corundum. It is the second hardest substance on earth after diamond, rating 9 on the Mohs scale of mineral hardness. Corundum itself is not a very rare mineral, but gem quality corundum is extremely rare. Most corundum is opaque to translucent and heavily included, suitable only for industrial use, including the production of abrasives used for sandpaper and machining of metal, plastics and wood. The name corundum comes from the Sanskrit word kuruvindam, meaning "ruby sapphire", while the name sapphire comes from the Persian word safir, derived from the Greek word for blue. In times of antiquity and the Middle Ages, the term sapphire actually referred to lapis lazuli, but in the early 19th century, the description and definition of sapphire was changed to the corundum variety we know today.

While blue is the most traditional and classic colour for sapphire, sapphire is actually found in a variety of different colours. Most natural sapphire is quite pale and light in colour. Only a small percentage of natural sapphire exhibits vivid and intense colours without some type of treatment or enhancement, the most common being heat-treatment. For many years, only blue sapphire was recognized as 'true' sapphire. Today, all colours of gem quality corundum are known as sapphire, with exception to red corundum, which is classified as ruby. There is no definitive demarcation between red ruby and sapphire; in most cases, near-red sapphire would be classed as inferior coloured ruby. Thus, it is common practice to trade near-red sapphire as a quality fancy colour sapphire, rather than as a lower grade ruby.

Coloured sapphire (other than blue) is often referred to as fancy sapphire, and fancy sapphire is typically traded using colour-specific names, such as yellow sapphire, green sapphire or purple sapphire. In the past, there were several misleading names used for fancy sapphire varieties, most of which are no longer used, such as 'Oriental peridot', a term which was used to refer to green sapphire.

Sapphire is any form of gem quality corundum, other than red. It is the second hardest mineral on earth next to diamond. Sapphire lacks cleavage, but can exhibit a conchoidal, uneven fracture. Chemically, sapphire is an aluminum oxide with a specific gravity or density ranging from 3.95 to 4.03 depending on the specific sapphire variety. Its refractive index ranges from 1.762 to 1.788 and its crystals can exhibit a weak level of double refraction or birefringence (0.008). Sapphire belongs to the trigonal crystal system, structured with three planes of symmetry and four axes. The exact crystal form depends on the specific variety and origin. Owing to sapphire's superior hardness and durability, it's nearly unmistakable, despite the fact that there are several other gem types that occur with similar colours and lustre. Some of the most easily confused gem types include spinel, zircon, beryl, tourmaline and chrysoberyl.

Sapphire; Origin and Sources Back to Top

Sapphire is found in only a few locations in the world. The three most famous regions for blue sapphire are Kashmir, Burma and Sri Lanka. Sapphire has also been mined in Cambodia, Thailand, Vietnam and India. As of 2007, Madagascar has been leading the world in sapphire production, though Sri Lanka continues to be the only steady producer of fine quality blue sapphire. Sri Lanka and Madagascar produce sapphires in a wide range of colors and whilst Sri Lanka has been a known sapphire source for centuries, sapphire deposits in Madagascar were only recently discovered in 1998. The enormous deposits found in the village of Ilakaka came as a big surprise and led to a gemstone fever reminiscent of the 19th century Californian gold rush. Today, Madagascar and Tanzania are considered to be two of the most important sapphire sources. Australia is also known for significant sapphire deposits, though most Australian sapphire is known to form rather dark in colour. In the USA, there are small sapphire deposits found throughout Montana and North Carolina.

The finest quality blue sapphire, based on past auction prices, comes from Kashmir and Mogok, Burma. The finest Kashmir and Burmese sapphires display superb colour and clarity without any thermal (heat) treatment. In recent times, limited resources in Burma have led miners to focus on more plentiful Burmese ruby. Some Sri Lankan (Ceylonese) sapphires are also unheated, but nowadays, the majority of sapphires have been heated, diffused or fracture-filled to improve colour and clarity, regardless of their origin. The Kashmir mines, high up in the Himalayas, have produced spectacular world-renowned gems, but since the 1920s, virtually no new material has been found. The rare, fine blue sapphires of Pailin, Cambodia were also very highly regarded by gem traders throughout the world. Pailin sapphires ranged in colour from light to deep blue, but they possessed a distinctive purity and intensity of colour that was unlike any other sapphire sources. Many gem traders graded them as close in quality to Kashmir and Burmese sapphires; and certainly superior to Sri Lanka (Ceylonese), Thai, American, Vietnamese, Indian, African and Australian sapphires.

Almost all the sapphires from around the world are cut and processed in Chanthaburi, Thailand. Along with Kanchanaburi and Trat, Chanthaburi was once one of main sources for Thai sapphire. Sapphire mining in Chanthaburi is mostly finished now, though there are a few small private mining locations scattered throughout the province. There is also a large market for Thai star sapphires that exhibit distinctive golden six-rayed stars. The golden black star sapphire is found nowhere else in the world. Nowadays, Chanthaburi, Thailand has become the main processing and trading centre for almost all of the world's sapphires, rubies and other coloured gemstones.

Buying Sapphire and Determining Sapphire Value

Sapphire Colour

Blue is the best-known 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 blue to dark blue. With blue sapphire, the intensity of blue is the most important factor. For example, a huge sapphire with a washed-out, weak blue color is much less valuable than a much smaller stone of excellent color. An intense, rich pure cornflower blue that is not too dark or too 'inky' is the most desirable colour. Overall, sapphires that are too dark or too light in colour are less valuable, but light-blue sapphires often have greater brilliance that is rarely found in darker blue stones. Colourless sapphires are actually quite rare, since most stones will exhibit some faint hints of colour.

Sapphire colors are best viewed under natural daylight. In artificial or incandescent light, sapphire colours can appear darker and inky black-blue. Many may even appear redder and less attractive than they really are. Sapphire colors are a result of trace impurities. The colouring agents found in blue sapphire are typically iron and titanium. Violet stones are coloured by vanadium. Pink sapphire and purple sapphire are often colored by iron and titanium impurities. Most yellow sapphire is naturally on the lighter side. It is through heat treatment that a more intense yellow golden colour is produced. Beryllium-treated sapphire may result in brilliant bright yellow. Small traces of iron can cause yellowish and greenish hues in stones. Chromium is known to produce fine pinks (and red in ruby), whilst iron and vanadium together can produce lovely orange stones. Padparadscha sapphire is a very rare sapphire with a pinkish-orange hue. A true padparadscha will always have a hint of pink. Many 'green' sapphires consist of fine alternating bands of blue and yellow sapphire, which are visible under a microscope.

Sapphire Clarity and Lustre

Sapphire can occur transparent to opaque. Transparent materials are the most valuable. Some translucent materials are cut into beads or cabochons. Opaque materials have very little gemstone value, although they may sometimes be used for ornamental carving. Sapphires are generally cleaner than ruby, so it is best to look for stones that are eye-clean. Eye-clean stones in larger sizes are quite rare, especially in ideal colours. In some cases, extremely fine silk throughout the stone can enhance the value of some sapphires. The famous sapphires from Kashmir have a velvety blue colour which is caused by this fine silk. This same silk causes the asterism seen in star sapphires. However, too much silk weakens the colour, rendering it an undesirable grayish colour. The rutile needles that are responsible for the silky shine reflect the light in sixty-degree angles. If the rutile needles are perfectly aligned in the same direction, the inclusions can result in six-rayed asterism when cut en cabochon and viewed under strong light. Sapphire exhibits an attractive vitreous luster.

Sapphire Cut and Shape

Various shapes and cutting styles are common with sapphires. Ovals, cushions, and rounds are commonly seen, as are other shapes, such as fancy hearts, pears and emerald cuts. Round stones can command very high premiums, especially in diamond-cut calibrated stones weighing 1 carat or more. Cabochons are common for translucent stones or for stones with visible inclusions. Briolettes, beads and tumbled sapphire can also be found, but is usually lower grade material.

Sapphire Treatment

The most common treatment for sapphire is heat treatment, though unheated specimens can be found. Stones are heated (generally before they are cut) to between 1700 to 1800 degrees Celsius (3100-3300 degrees F) for several hours. Most sapphires today are heated, and unheated stones in rich blue can command enormous prices in today's market. Some blue sapphires may also be diffusion treated, though this treatment is more common for star sapphires. Beryllium treatment is now being used to produce stunning orange and red colours that were once rarely seen. All sapphire treatments should be fully disclosed by any reputable dealer.

TOP

Sapphire

Color: any color

Hardness: 9

Refractive index: 1.76 - 1.78

Density: 3.99 - 4.00

Chemical composition: Al2O3

Crystal structure: hexagonal

Origins: Burma, Sri Lanka, India, Madagascar, Kenya, Tanzania, Thailand, Cambodia, China, Australia, USA.

Sapphires are a variety of corundum, existing in almost all colors. A sapphire's color is the main factor for price estimation. Heat treatment is usually applied to improve their color and reduce small inclusions. It can be difficult to exactly identify the color online, therefore we recommend that you refer to Gemval.com for an appraisal. Please accept that a value-approximation error in the 15-20% range is possible.