Gems in SriLanka

8/8/2019 Gems in SriLanka

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B cr vrt t Cr rpc.

Cpt: Aluminium oxide with traces ofiron and titanium

Prprt: Hardness- 9; Density: 4.0;

Rrctv : 1.776 – 1.770; Birefringence: 0.008

Cr: Blue, violetish blue in varyingtones

Vt: Most valuable and most favouredof coloured gemstones

There is a wide range of views among the originof the word Sapphire. One is that it may haveoriginated from Sanskrit, meaning precious to theSaturn Sanipriya ( Sani = Saturn, Priya = Precious).Buddhist monks who moved to Middle Eastintroduced the stone as Sani piriya and eventuallybecome sapir and sapphire.

Blue sapphire is associated with Saturn and isthe birthstone for September. The 45th weddinganniversary is known as the sapphire anniversary.

‘Blue sapphires from Sri Lanka have a unique beautyall their own, … Rakawana stones are of particularnote with their colour compared to that found on thetip of a peacock feather or that on a peacock neck’

‘Sri Lanka is the world’s most prolific producer ofgiant sapphires (of more than 100 carats)’

Richard W Hughes

TwelVe PoPulaRGemsTones fRom sRi lanka

saPPhiRe

Blue colour of Peacock neck

R cr vrt t Cr rpc.

Cpt: Aluminium oxide with traces ofchromium



Cr: Red with a trace of violet. Also calledpigeon blood red. Red fluorescenceintensifies the body colour.

Vt: Most valuable of all coloured gem-stones

The name ruby was derived from the Latin wordrubens, meaning ‘red’. Ruby red colour representslove, passion and power.

Ruby is the birthstone for July and associated withZodiac signs Leo and Cancer. Ruby is associated withthe Sun in Vedic astrology. It is the gemstone for 40thwedding anniversary

Ruby is the king of coloured gemstones and alsothe magnificent red variety of the multi-coloured

corundum species, with bright red of body colourand fluorescence, supreme hardness and toughness,outstanding brilliance and luster and the highestvalue of all coloured gemstones for the rarity. Brightred colour of ‘Burmese ruby’ from Mogok valley inMyanmar is in the top place in demand. Rubies fromSri Lanka are of higher brilliance, with a trace ofviolet.

“Top grade Sri Lanka reds (rubies) are virtuallyindistinguishable from their Mogok brotheren”

Richard W Hughes

RuBy

View of a gem mining area in Sri Lanka



P vrt t Crr pc

Cpt: Aluminium oxide with tracesof chromium and yellow colourcentres


Rrctv : 1.776 – 1.770; Birefringence: 0.008Cr: Pink with a mixture of yellow/

orange- Compared to colour ofthe Lotus Flower. Fluorescence ofred and orange.

Vt: It is one of the most beautifuland valuable gemstones, and theprices vary greatly according tosize and quality.

The term Padmardscha is derived from the Sanskrit/ Sinhalese padmaraga, the colors seen in the lotus

flower with pink petals and yellow colour pollen. Itis the special variety of the corundum species, in anextraordinary mixture of pink and orange colours.Some define the gem’s color as a blend of lotus flowerand sunset.

‘The original locality for Padparadscha was SriLanka (Ceylon). Fine stones have also been found inVietnam’s Quy Chau district, Tanzania’s Tundurudistrict, and Madagascar.” AGTA GTC’s Laboratory Update for July 12, 2005

PadmaRadsCha

The colors seen in the lotus flower with pink petals and yellow colourpollen.

Cr cgg vrt t Crbr rpc.

Cpt: Beryllium aluminium oxide withtraces of chromium

Prprt: Hardness- 8.5; Density: 3.71;

Rrctv : 1.745– 1.754; Birefringence: 0.009

Cr: Green body colour for day lightchanging to red colour undertungsten light

Vt: One of the most valuablegemstones, and the prices vary

greatly according to size andquality.

This gem was named in honour of tsar princeAlexander Nicolajewitsch on the occasion of hiscoming of age at his 16th year, on his birthday of 17thApril, 1834 as future Tsar Alexander II. during whichtime the Russian imperial colours were also red andgreen.

Sri Lanka is one of the suppliers of Alexandrite andAlexandrite Cat’s Eye varieties

Alexandrite is reputed to aid creativity and inspirethe imagination. It is also considered a stone of verygood omen. In critical situations, when logic is notthe answer, the wearer of this gem will be helped toovercome by strengthening his intuition. Alexandriteis the gemstone for 55th anniversary

“If you love magic, especially the magic of science,you’ll love alexandrite, the color-change gem.Outside in daylight, it is a cool bluish mossy green.Inside in lamplight, it is a red gem, with a warmraspberry tone. You can watch it flick back and forthby switching from fluorescent to incandescent light.”

AGTA Gemstone Information.

alexandRiTe

View of a gm mining area in Sri Lanka



Ct’ vrt t Crbr pc.

Cpt: Beryllium aluminium oxide andsilky inclusion

Prprt: Hardness- 8_; Density: 3.71:

Rrctv : 1.745– 1.754; Birefringence: 0.009

Cr: Brown, green, yellow and their

mixed hues. Special optical effect:Chatoyancy, the cat’s eye effectdue to oriented fine silky inclu-sions.

Vt: One of the most valuablegemstones, and the prices varygreatly according to size andquality.

Cat’s Eye and Alexandrite Cat’s Eye varieties of theChrysoberyl species are found in Sri Lanka gemgravel, some of which are of top quality and in largesizes. ‘Ray of Treasure’ Cat’s Eye of 105 carats is a

part of the gemstone collection of the National Gem & Jewellery Authority.

Cat’s Eye is the variety of Chrysoberyl specieswhich is believed to posses some special qualities.It has been regarded as an effective protective stoneand talisman gemstone to keep disaster away.Chrysoberyl with its golden tones, is often associatedwith wealth, a reason to consider that its Cat’s Eye isone among the gemstones of the luxury class.

This gemstone helps to maintain discipline and

self-control, promote concentration and the abilityto learn, and enable the wearer to think clearly andfar-sightedly. It also transforms the negative thoughtsof the wearer into positive energy, and promotestolerance and harmony.

CaT’s eye

Cat’s eye – two ways of Nature’s creation for reaction of light

B cr str vrt t Cr rpc.

Cpt: Aluminium oxide with traces ofiron and titanium for colour andoriented fine rutile needles inthree directions.



Cr: Blue, violetish blue in varyingtones

Vt: Star Effect with bright silky raysin three directions

Some of the giant Star Sapphires from Sri Lankaare; “Star of Artaban” (316 carats) and the “BismarkSapphire” of (98.6 carats), both in Smithsoniancollection, “Star of India “ and “Midnight Star”(116.75 carats), both in American Museum of NationalHistory in New York and also the finest 393 carat“Star of Sri Lanka” in possession of the National Gem& Jewellery Authrity

“Over the years Sri Lanka has produced somefantastic natural blue sapphires of large, both facetedand stars. These include top quality gems in the100 – 300 ct range. Many of the largest sapphiresin museum collections around the world haveoriginated from the gem gravels of Sri Lanka.”

Richard W.Hughes

sTaR saPPhiRe

It is one of the lucky stones for those born under

the sign of Leo. Cat’s Eye is the gemstone for 18thanniversary

Manual river dredging for gemstones in Sri Lanka



Red coloured Star variety of the Corundum mineralspecies

Composition: Aluminium oxide with tracesof chromium for colour and ori-ented fine rutile needles in threedirections.

Properties: Hardness- 9; Density: 4.01

Refractive index: 1.776 – 1.770; Birefringence: 0.008Colour: Red, violetish red in varying

tones

Special OpticalEffects:

Star Effect with bright silky raysin three directions

Valuation: One of the valuable gemstones

This phenomenon of asterism, producing star effectis caused by very fine needles of rutile oriented inthree directions. When perfectly cut, the six-spokedstar will be seen to glide magically across the surfaceof the stone when the latter is moved. The value

depends on the beauty and attractiveness of the hotred colour and transparency, in addition to the wellcentred strong and sharp rays of the star.

Sri Lanka Star Rubies are light red, like riperaspberries. But, with very bright rays of the star.

STAR RUBY

Gem gravel brought to cane baskets for washing

A variety of the feldspar group- Potassiumaluminium silicate with special optical effect of

schiller called Adularescence

Properties: Hardness - 6 – 6.5; Density- 2.56;

Refractive index: 1.520 – 1.539; Birefringence: 0.008

Colour: Moonstones come in a variety ofcolors. The body color can rangefrom colorless to white, gray,brown, yellow, green, or pink. Itsbeauty is produced by white orblue schiller effect.

Identification of moonstone is the display of shimmer,caused by the intergrowth of two different varietiesof feldspar, with different refractive values. Itscharacteristic inclusion is called ‘centepede’ or‘Chinese aeroplane’ which is due to fine cleavagefractures in to two directions.

“The ancient Romans theorized that moonstone,with its unearthly shimmer, was formed from frozenmoonlight. This appealing gem variety does shinewith a cool lunar light but it is the mineral feldspar,quite terrestrial in origin.”

Moonstones from Sri Lanka, the classical country oforigin of the moonstone, shimmer in pale blue on analmost transparent background. The best variety withblue sheen is mined in Southern Sri Lanka in an areanear Ambalangoda, which had formed in a rock typecalled pegmatite.

MOONSTONE

Washing and paning of the gem gravel



Cpt: Is fluo containing aluminiumsilicate

Prprt: Hardness 8; Density: 3.53;


Cr: Colourless, pink, blue, yellow,orange, brown

Topaz sometimes has the amber gold of fine cognacor the blush of a peach, and all the beautiful warmbrowns and oranges in between. Some rare andexceptional examples are pale pink to a sherry red.

Blue, once the most rare color of topaz, is today themost common, due to a stable enhancement processthat turns colorless topaz to blue. After irradiationit turns to brown and then heated to sky blue. Thisenhancement process is permanent. Topaz from SriLanka had become most popular for this treatment.

“The Egyptians said that topaz was colored withthe golden glow of the sun god. Legend has it thattopaz dispels all enchantment and helps to improveeyesight. The ancient Greeks believed that it hadthe power to increase strength and make its wearerinvisible in times of emergency.” AGTA

The birthstone for November, topaz is a talisman forthe sign of Sagittarius and is the suggested gift for the23rd anniversary.

ToPaz

Garnet is the group of six gem quality species in anintermixing compositions, representing more than tenvarieties in different colours, but with exception forblue colour. Red is the most often encountered colour,which appears in varying hues and tones, producedfrom the combination of almandine-pyrope species.

Cpt: Magnesium-iron aluminiumsilicate

Prprt: Hardness 7__7_; Density: 3.7– 4.2;

Rrctv : 1.74 – 1.79, Singly refractiveCr: Red, purplish red, pale to deep

mauve

Name garnet is derived from Latin granum (seed)meaning grainy, which has its origin from Sanskrit.This makes the reference to typical roundest shape ofgarnet crystals in rhombdoceahedral or trapezohedralhabit and also to the pink to red colour, remindingthe similarity in appearance to seed of a ripepomegranate.

Garnets were known to man for thousands of years.They are found in jewellery from early Egyptian,Greek and Roman times. Early explores liked to carrygarnets with them in consideration as a talisman andprotective stone, by believing it to light up the nightand protect the bearer from evil and disaster. It wasalso the belief that these gems would bestow upontheir wearer a variety of love sentiments, including:commitment and devotion. Fiery red pyrope garnetswere popular in the Victorian period as Bohemiangarnets which were coming from Bohemia (inEurope). Rhodolite is the

RhodoliTe GaRneT-Prp a mtr

Nambuwa the wased gem gravel

This hand machine is used even today to cut and polish Star and Cat’sEye gemstones into cabochon styles.



Cpt: Zirconium silicate

Prprt: Hardness 7_ _ 6_ Density: 4.8 to3.9;

Rrctv : 1.92– 1.99 to 1.76-1.84;

Brrgc: 0.059 to almost none in metamictstones

Cr: Colourless, pink, blue, yellow,orange, brown

Name probably comes from Persian word zargunmeaning “gold coloured”, although it is found in aother colours.

Zircon comes in a wide range of colours, and formany years, the most popular was the colourlessvariety, which looks similar to diamonds than anyother natural gemstone, due to its high brilliance,refraction and dispersion. This material was knownas Matara diamond, for being originated in RakwanaHills in the Southern part of Sri Lanka, in itsdestination in Europe.

It was the tradition to produce blue, yellow and

colourless varieties by heat treatment, which isaccepted by the trade. Zircons also found in othercolours of green, red, brown and orange.

In the Middle ages, it was in belief that zircon wassaid to help sleep, bring prospectus and promotehonour and wisdom to its owner. Hindu poetsmention of Kalpa Tree (Kalpa Wruksha) the ultimategift of the gods, a glowing tree covered in gemstonefruits with zircon of leaves.

ziRCon

Blue, colourless and brown zircon from Sri Lanka

pyrope and almandine mixed variety with varyingtones of violetish red colour coming from most ofgem mining areas in Sri Lanka.

Garnet is the gemstone for 2nd anniversary and thebirthstone for the month of January.

Black Prince’s Ruby- a red spinel in natural crystal from with CullinunII diamond and other gems in the English Imperial State Crown

sPinelCpt: magnesium aluminium oxide

Prprt: Hardness 8; Density: 3.60;

Rrctv : 1.72, single refractive

Spinel exhibits in a wide range of colours from nearcolourless, through shades of orange, and pink tored, pale blue through deep blue to dark blue, bluish

green and black.

Spinel is the end member of a group of species withproportional intermixing (isomorphism), with itsother family members of ceylonite, pleonaste andhercinite with ferrous iron, gahnospinel and gahnitewith zinc, chromite with chromium, chlorospinelwith ferric iron and rare cobalt spinel with cobalt.

Spinel is known as the greatest imposter in gemstonehistory, by occupying in many crown jewels asfamous rubies. The famous Black Prince’s ruby in the

Imperial State Crown of England of the British Crown Jewels is a 170 carat red spinel. The Timor Ruby nowowned by Queen Elizabeth and with the names ofsome of the Mogul emperors who previously ownedit being engraved on its face is a 361 carat red spinel.

Even today strong red spinels from Burma andbright blue spinels from Sri Lanka impose confusionfor ruby and sapphire. On the other hand, two bluerarities- cobalt spinel and gahnospinel, both foundin Sri Lanka bring delight to collectors. Taaffeitewith a similar appearance in colour but belongs toa different species is a rare gemstones found in gemgravels in Sri Lanka along with spinels.

Spinel is the gemstone for 22nd anniversary

Curtsey: Dayananda Dillimuni FGA, DGemG - Consultant Gemologist

Design & Concept by Anoma Weralupe

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Gems in SriLanka