Gemstone literature an amazing experience all over the world.

Written by Alain Darbellay

2004 All rights reserved.

Extracts of Articles

Amethyst The art of lapidary is to placerepparttar color correctly in order to make homogeneousrepparttar 124184 tone ofrepparttar 124185 cut stone. The distribution ofrepparttar 124186 color in a cut stone is observed simply by immersing it in water contained in a transparent container and colourless. Corundum Corundum is composed of pure alumina; its colouring is due to metallic oxide traces or inclusions. Gems are generally found in alluvium, but come either from basaltic slag, or from metamorphosed limestone.

Tourmaline Coloured tourmalines are related to sodolithic pegmatite. One distinguishes two principal types of tourmalines:repparttar 124187 hexagonal type andrepparttar 124188 triangular one.

The Mine of Anjanabonoina, located inrepparttar 124189 high plateaus, produced rubellites, green tourmalines, and a variety of rare stones. Garnet

The Besafotra river carryrepparttar 124190 spessartites on several kilometers from their source, doubtless a sodolitic pegmatite. Tanety "grounds borderingrepparttar 124191 river," are alsorepparttar 124192 object ofrepparttar 124193 orange garnet's fever. Malaya Garnet Discovery This marvellous chromium-spessartite garnet from Madagascar was discovered in its bedrock in 1996. This discovery remains exceptional byrepparttar 124194 quality of its product and also byrepparttar 124195 fact that it wasrepparttar 124196 second deposit inrepparttar 124197 world to deliver this type of Malaya garnet. Crystalline Systems 7 systems of crystallization: There are 32 possibilities of combinations ofrepparttar 124198 elements of symmetry. Allrepparttar 124199 geometrical operations which cause a repetition ofrepparttar 124200 pattern are called operations of symmetry. Cutting Styles

Table, Crown, Girdle, Pavilion, Culet. Fancy Styles Back to Top Shield Cut, Trillant Cut.

Cutting Characteristics When a stone is cut according to good proportions,repparttar 124201 light is reflected from one facet to another and arises byrepparttar 124202 top.


Microscopes:repparttar 124203 binocular one, i.e. to double objective is best adapted for gemology. The microscope is of first importance inrepparttar 124204 detection of counterfeits. Indeed,repparttar 124205 study of inclusions whichrepparttar 124206 stone can contain is a practical means to identifyrepparttar 124207 gems while explaining to a certain extentrepparttar 124208 conditions under which they were formed in nature. Size & Weight Back to Top Sapphire, Ruby, Emerald. Madagascar gem safari

Diamond Flashes

Written by Laura Ciocan

Beyond magnificence and splendor,repparttar world of diamonds evolves on stirred grounds. Whenrepparttar 124183 stake is so important, interests collide. But technology develops following its onward course. Here are some interesting off-stage events inrepparttar 124184 diamond industry and innovations in technology.

De Beers sued by head ofrepparttar 124185 Diamond Bourse

Derek Parsons,repparttar 124186 president ofrepparttar 124187 Diamond Bourse ofrepparttar 124188 Southeast United States has filed a lawsuit against De Beers, onrepparttar 124189 charge ofrepparttar 124190 company's disregard of American competition law. Their Supplier of Choice policy putsrepparttar 124191 American dealers at a disadvantage. The suit was not launched on behalf ofrepparttar 124192 Miami bourse but on behalf of diamond dealers in America, condemningrepparttar 124193 criteria on which De Beers makesrepparttar 124194 sales they would sell only to their sightholders, discouragingrepparttar 124195 non-sightholders and keeping prices artificially high at a non-competitive level.

Diamond mining expands

De Beers holds control of only 50% ofrepparttar 124196 roughs market

Diamond rising prices have stimulatedrepparttar 124197 exploration and mining in more countries such as Canada, Russia, Angola, India, Brazil. Nevertheless, about 40% of diamonds still come from Botswana and South Africa. De Beers' control onrepparttar 124198 rough diamond market was declared to have decreased from 70% to about 50%. Canada, Russia and West and Central Africa are considered by specialists an important potential diamond source. India and Brazil are prospected by geologists also due torepparttar 124199 fact that they are known to have been a diamond source inrepparttar 124200 past.

The largest diamond reserve of Africa lives in extreme poverty

Althoughrepparttar 124201 fourth largest producer inrepparttar 124202 world by value andrepparttar 124203 holder ofrepparttar 124204 largest diamond reserves in Africa. Angola's per capita gross national income GNI is estimated at $650 per annum. People' s main means of subsistence is agriculture. The diamond sector has been seriously affected byrepparttar 124205 long war and by gem smuggling. Yet it still represents a very important potential driver of economic development. Since 2002, whenrepparttar 124206 conflict betweenrepparttar 124207 government andrepparttar 124208 UNITA rebel movement ended, developingrepparttar 124209 sector has become a national priority andrepparttar 124210 government has already made changes torepparttar 124211 diamond sector regulations. Serious redevelopment and investment is needed in this area. At present, artisanal mining operates in Angola and it brings very little economic benefit to local communities.

Increasing conflict in Russia between diamond cutters and miners

The Russian company Alrosa isrepparttar 124212 largest diamond miner inrepparttar 124213 world outside De Beers. Diamond cutters accuse Alrosa of favoring exports and providing larger stones forrepparttar 124214 foreign market and offering only small-sized diamonds torepparttar 124215 internal market. Onrepparttar 124216 other hand, Alrosa says that cutters cannot be allowed to pickrepparttar 124217 assortment of size they want. The result is that Russian cutters are buying million dollars in rough stones from South Africa each month. Russian manufacturers had a production of $1.1 billion in 2003, and Alrosa is estimated to produce around $2 billion worth rough diamonds this year.

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