Nata Heng Schluessel, GG logo Roland Schluessel, FGA

Spinel

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Spinel deposit in Southern Madagascar. Spinel and Sapphire mine: sorting of the gemstone bearing gravel.

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It wasn’t until 1783 that red Spinel and Ruby were identified as different minerals. Despite their attractive color and their high hardness and durability, red Spinels are not as popular as Rubies. The main reason is a lack of sufficient quantities for successful marketing. Spinels in large sizes are scarce and the small production is limited to a few sources, mainly in Mogok in Myanmar ( Burma).

Blue, pink, orange and yellow Spinels are found in Sri Lanka, Madagascar and Tanzania. Historically important sources for gem Spinels were also located in Afghanistan and in Pamir.

PILLAR & STONE INTERNATIONAL offers Red and Pink Spinels ranging from 1 carat to 8 carats in size.

Red Spinel

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The Valley of Mogok in Burma is the most important source for red Spinels worldwide. Because of their perfect shape, rough Spinel crystals from Burma are called angel cut.

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A red Spinel of high quality is the only natural gemstone which resembles a fine Ruby. In fact, Spinels are generally found together with Rubies and Sapphires in most gem deposits and like the Ruby, owes its vivid red color to a small content of chromium. The Spinel is a mineral species in itself and even if not as popular as it would deserve, stands as its own as an attractive precious stone. Its physical properties are among the best within the world of gemstones and make him greatly suitable for fine jewelry. Fine Spinels over 3 ct are scarce and faceted stones over 5 ct, showing a pure vivid red color are among the most desirable collector’s gemstones.

WHAT IS A GEM RED SPINEL?

PROPERTIES:

Best color = Vivid red, not too dark and not too light, without overtone of brownish, orangey or lilac.
Popular expression for the best color = “Burmese Ruby-red”.
Optic character = Spinel is singly refractive and shows the same color in all 3 directions.
Fluorescence = Inert to strong orange, orange-red and red.
Transparency = Transparent.
Clarity = Minute inclusions are generally accepted but eye clean stones are the most desirable.
Brilliancy = High.

FACET CUTS:6

Cushion cut = Is the ideal and most common cut for a red Spinel.
Oval = Very suitable cut for red Spinel.
Round = Generally available for small stones only.

PHYSICAL PROPERTIES:

Hardness = 8
Toughness = Good.
Cleavage = Poorly developed and not seen in gemstones.
Refractive Index = 1.718
Specific Gravity = 3.60

CLEANING METHODS:

Ultrasonic and Steamer = Usually safe.
Warm soapy water: Usually safe.

STABILITY :

Reaction to heat = Stable.
Reaction to light = Stable.
Reaction to chemicals = Stable.

MAJOR SOURCES:

Mogok in Myanmar ( Burma) is the major source. Also from Tanzania, Sri Lanka (Ceylon), Madagascar, Afghanistan.

STRONGEST PRICE JUMPS:

3 ct, 5 ct, 8 ct and 10 ct sizes.

ENHANCEMENTS:

None.

IMITATIONS:

Synthetic Spinel, assembled stones (e.g. glass doublet).

MOST RESEMBLING GEMSTONE:

Ruby.

 

 

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