1. Cullinan/Kulien Diamond: Largest gem quality rough diamond. 3106.75 Carats found in 1905 - Part of the British Crown jewels.
2. Golden Jubilee: Largest gem quality cut diamond - yellow brown colour - Found in 1985 - Now held by King Bhumibol Adulyadej of Thailand. Previously it was known as "Cullinan I" and "Great Star of Africa ".
3. Centenary Diamond: Colourless and flawless diamond - 273.85 carats. Now with De Beers Diamond Co.,
4. Millenium Star: Top Color flawless peer shaped diamond. 203.34 carats. Owned by De Beers Diamond Co.,
5. Hope: 45.52 Carats (9.10g) now with the Smithsonian Institute. Deep Blue Diamond.
6. Kohinoor: 105 carats (21.6g) mined from Kollur in AP. After passing few Indian rulers it finally went over to the British and it is new part of the crown jewels.
7. Darya I noor: 182 Carats - 36g - now with Iranian Crown Jewels. Mined from Kollur mines in AP. Through history it went over to Iranian rulers.

Kohinoor: Lastly, it was with Sikh Kingdom of Punjab. Given to the British by the Sikh King Duleep Singh, as part of the Lahore Treaty, 1846.

Kimberley.

Surat, India.

Antwerp, Belgium.

Panna in Madhya Pradesh.

ARGYLE diamond mines in Australia. Famous for Pink Diamonds and Produces 90 to 95% of world's supply.

Botswana, Russia and South Africa in that order.

ORAPA diamond mines in Botswana.

By volcanic eruptions.

Formation of diamonds require exposure of carbon bearing materials to High pressure ranging between 45 to 60 kilobars, but at a comparatively low temperature range between 900 to 1300 degreeC. These conditions are available in the Lithospheric mantle, below relatively stable continental plates. Diamonds also form in places where the meteors have struck, as the meteors create craters by impact and also create shock zones of high pressure and temperature.

Nitorogen presence.

Generally in Brown and Yellow and also white or clear. Other coloured diamonds normally have impurities.

Polishing, Cutting, Diamond tipped drill bits and cutters etc.,

Yes, only another diamond.

Aggregated diamond nanorods.

LONS DAELITE - Discovered in February 2009. A mineral made of Carbon atoms like Diamond, is 58% harder than Diamond.

6420 degree F.

No. 10 - the hardest.

Crystalline. (octahedral)

Colourless.

Extreme hardness, High Dispersion Index, and High Thermal Conductivity.

A transparent crystal of tetrahedrally ( a space filling tessellation) bonded carbon atom.

Cullinan/Kulien - 3106.75 carats.

Aurora: Natuaral color diamonds on display at American Museum of Natural History, New York.

Diamond cutting is an art. There are mathematical guidelines for the angles and length ratios at which the diamond is supposed to be cut in order to get the proper prism arrangement for maximum amount of light reflection.

1. Point Cut 2. Table Cut 3. Old Single cut 4. Mazanine cut 5. Peruzzi Cut6. Old European Cut 7. Fancy Cuts - Princess Cut and 8. Round Brilliant.

Marcell Tolkowsky - Belgium.

Surat, Gujarat.

Rapaport Report: It is the standard pricing index based on the colour, Clarity, weight, cut etc.

The best quality.

India - world's 68% cut diamonds are from India.

Chemical Symbol -- Au. ISO Currency code - XA  Atomic Number - 75 and Food Code - E 175.

A yellowish metal, occurring as nuggets or as grains in rocks and alluvial soil.

1. It is the most malleable and ductile metal.
2. Does not react with most chemicals, but is attacked by Chlorine, Fluorine Aqua Regia and Cyanide.
3. Dissolves in mercury and forms an amalgam of alloys.
4. It is insoluble in Nitric Acid, while all other metals will dissolve. Thus Nitric acid was used to confirm the presence of gold. Thus came the origin Of the colloquial term " acid test ".
5. Gold is good conductor of heat and electricity.
6. Does not get affected by most reagents. Heat, moisture, oxygen and most corrosive agents have very little effect on gold; thus making it well suited for use in coins and jewellery. Conversely, halogens (non metal elements like fluorine, chlorine, bromine, Iodine, astatine etc) will chemically alter gold. Aqua Regia - (a fresh mixture of concentrated nitric acid and Concentrated Hydrochloric acid) dissolves gold, by virtue of elemental chlorine generated by this acid mixture.

By carat equivalent to 220 milligrams. K is the symbol for carat. 24 K is the purest form of gold.

Wohlwill Process, Miller Process.

The process of extracting gold from sea water. Invented by Fritz Haber of Germany.

1. White Gold: Gold+Platinum, Palladium, nickel and/or zinc used as a substitute for platinum.2. Green Gold: Gold + Silver.3. Rose Gold: Gold + Copper.4. Blue Gold: Gold + Iron.5. Purple Gold : Gold + Aluminium.

South Africa.

A system of unit of mass mentioned in grams.

Refined pure gold are made into bars of different sizes, shapes and weights called ingots. Their purity is expressed as a decimal figure ranging from 0-1 known as the "Millesimal Fineness", such as 0.995 being very pure.

Gold Standard: A monetary system in which the standard economy unit of account is a fixed weight of gold. In the international economic scene, gold forms the basis for a monetary Standard, by the International Monetary Fund, and the Bank for International settlements. Stock of gold, in a country exhibits economic Value of a country.

Institutions set up to assay or test the purity of precisous metal items to protect the consumer interest.

A mark or series of marks, struck on items made of precious metals, like Platinum, Gold etc., to guarantee the purity or fineness of the metal. It is awarded by the Assaying Office. BIS - Bureau of Indian Standards ( formerly ISI - Indian Standards Institution) are the statutory authority in India to Hallmark Gold ornaments Etc., under the provisions of BIS Act of 1986.

Hill End, New South Wales.

916 stands for 91.6% of gold in the ornament. (22K gold).KDM stands for Cadmium (Kaedmiam) used in soldering of jwelleries.

Chemical symbol - Pt ; Atomic Number - 78; ISO Currency Code - XPT.

A grayish white metal, malleable, ductile and precious. Occurs in Nickel, Copper ores and also as native deposits.

1. Resistant to Corrosion. 2. Does not oxidize in air at any temperature. 3. May corrode in cyanides, halogens, sulphur and caustic alkalis. 4. Insoluble in hydrochloric and nitric acid, but dissolves in Aqua Regia.

1741 - Charles Wood - A British scientist.

Jwellery, Laboratory Equipments, Electrical Contacts, Dentistry, and Automobile emission exhaust system because of its high catalystic properties.

Pt 950.

South Africa and Russia (about 90%)

Tamilnadu - Sittampundi in Namakkal Dt.,(covering Karungalpatti, Chettiyampalayam and Tasamapalayam) and Mettupalayam near Coimbatore(covering Solavanur, Mallanayakkam Palayam and Karappadi )

Chemical Symbol - Pd; Atomic Number - 46; ISO currency Code - XPD.

A silver white metal belonging to the Platinum Group.

William Hyde Wollaston in 1803, discovered it in the Platinum Ores and Named after an asteroid called Pallas.

Usually found as a free metal along with Platinum ores, and also commercially extracted from copper, nickel ores.

1. Used in jwellery sometimes.
2. Used as catalyctic converters on cars and in organic industry.
3. It has a great affinity for Hydrogen and able to absorb 900 times, its own volume of the gas and plays a vital role in cold fusions.
4. Used in Watches, Aircraft Spark Plugs, Surgical Instruments, electrical Contacts and in dentistry.

Chemical Symbol - Ag; Atomic Number - 47; ISO currency code - XAGFood Code - E 174.

1. This metal is found in its native form(ground) with sulphur, arsenic, antimony or chlorine and in various ores such as Argentite (Ag2s), Horn Silver (AgCl) and Pyrargyrite.
2. The principal source of silver are copper, copper nickel, gold, lead, And lead zinc ores, obtained from Peru, Mexico, China and Australia.
3. This metal can also be obtained during the electrolytic refining of Copper and by application of the "Parker Process" on lead metal/lead Ores that contains small amounts of silver.

It is a pyrometallurgical industrial process for removing silver from lead, during the production of bullion (bars of gold or silver before coinage) -Invented by Alexander Parker in 1850.

1. Malleable and ductile - but less malleable than gold as it is harder than gold. 2. Poor reflector of ultra-violet light. 3. Has the highest electrical and thermal conductivity.

1. Silver Carbonate: Used to remove Carbon-di-oxide from the air.
2. Silver Chloride: i) can be made transparent and used as a cement for glass.ii) widely used as pH(a measure of acidity or alkalinity of a solution) testing and potentiometric (variable resistor that can be used as a voltage divider) measurement.
3. Silver Fulminate: A powerful explosive.
4. Silver Iodide: Cloud seeding for rains.
5. Silver Nitrate: Important compound widely used for photo processing.
6. Silver Oxide: Used as a positive electrode(cathode) in watch batteries.

Sterling Silver: 92.5% pure silver + other metals specially copper. The Minimum Millesimal Fineness is 925.

Oxygen than any other gas.

A monetary system in which the standard economic unit of account is a fixed weight of silver.

Peru and Mexico in that order.

Chemical Symbol - Fe;   Atomic Number -- 26.

An abundant metal on earth, extracted from "Haematite". A metal in use Almost all areas and it is the most widely used metal right from pin to ship.

Melting point - 1811K = 1538 degreeC = 2800 degree F.    Boiling Point -- 3134K = 2861 degreeC = 5182 degreeF.

Pig Iron: It is raw Iron, an immediate product of the Iron ore with coke and limestone in a blast furnace. It has high carbon content is 3.5 to 5% making it very brittle. Used in a very limited areas only.
Cast Iron: A type of Iron with 2 to 4% Carbon, 1 to 6% silicon and a small Quantity of Manganese.
Wrought Iron: With only .15% carbon, it is tough, malleable, ductile and Weldable. Not useful for making blades and swords.
Iron Oxides: Also called ferric oxides, haematite, red iron oxide, synthetic maghenite, colcothat or simply rust. Often used in magnetic storage, that is, magnetic layer or floppy discs and many other fields.

Electroplating, Galvanizing and painting.

1. Iron Acetate: Used in dyeing of cloth.
2. Iron Ammonium Oxalate: Used in Blue Prints - paper based reproduction of technical drawings, documenting an architecture or an engineering design.
3. Iron Arsenate: Used in insecticide.
4. Iron Chloride: Used in water purification, sewage treatment, dyeing of Cloth, colouring agent for paints, additive in animal feed, and as an Etching material for engravement, photography and printed circuits.
5. Iron Chromate: Used as a yellow pigment for paints and ceramics.
6. Iron Hydroxide: Used as a brown pigment for rubber and for water Purification.
7. Iron Phosphate: Used in fertilizer and as an additive and animal food.
8. Iron Acetate: Used in fabric dyeing, leather tanning and as wood preservative.
9. Iron Gluconate: Used as a dietary supplement in iron pills.
10.Iron Oxalate: Used as a yellow pigment for paints, plastics, glass, Ceramics and photography.
11.Iron Sulphate: Used in water purification, sewage treatment, as a catalyst in ammonium production, as an ingredient in fertilizer and herbicide, as an additive in animal feed, in wood preservative and as an additive to flour to increase iron level.

An alloy consisting mostly of iron with a carbon content between 0.02 to 1.7% for different grades of steel.

From molten pig iron, through a process called "Bessemer Process" - removal of impurities from the iron by oxidation, through air being blown through the molten iron. The process is named after Henry Bessemer, who patented the process in 1855.

1. Carbon Steel: An alloy of Iron and Carbon, with manganese upto 1.65%, Silicon upto 0.60% and copper upto 0.60%.
2. HSLA Steel: A type of steel that is stronger and tougher than ordinary carbon steel with the combination of - Carbon 0.15%, Manganese 1.65%, Phosphorous and Sulphur below 0.35% and small quantity of copper, Nickel, Niobium, Nitrogen, Vanadium, Chromium, Molybdenum, Silicon, or Zincomium. Used in automobiles, structural constructions, bridges etc.
3. Tool Steel: A special type of steel with 0.7% to 1.4% carbon, with low manganese content (to minimize cracks) and manufactured under careful controlled conditions.
4. High Carbon Steel: 0.6 to 0.99 % carbon content - very strong, used for Springs and ropes.
5. Low Alloy Steel: A steel alloyed with other elements usually molybdenum, manganese, chromium, vanadium, silicon, boron or nickel, upto 10% by weight to improve harden ability of its thick sections.
6. Stainless Steel: An iron carbon alloy with a minimum of 10.5% chromium content. It does not stain, corrode or rust. Has wide use in cookware, cutlery, hardware, surgical instruments, appliances, equipments, automotive and aerospace assembly and building materials. There are different varieties depending upon content. Salem in Tamilnadu has a plant.
7. Mild Steel: Low carbon content - 0.05 to 0.29% - low tensile strength - malleable - surface strength or hardness can be increased through carbonizing - a process by which carbon is introduced into the metal.
8. Medium Carbon Steel: Carbon 0.30 to 0.59%. Balances ductility and strength and has a good wear resistance. Used for large parts of forging and automotive components.
9. Ultra High Carbon Steel: 1 to 2% carbon. Can be tempered to great Hardness and used in manufacture of knives, axles and punches.

El Cerro Mutun, in Bolivia.

Australia.

Arcelor Mittal - owned by Laxmi Ratan Mittal of India.

A process for primary steel making where iron ore is processed almost directly into steel.

Chemical Symbol - Pb; Atomic Number -- 82.

A soft, heavy, toxic and malleable metal comes in bluish white when freshly cut and becomes dull grey when exposed to air. Native lead occurs very rarely. Its main minerals are Galena, Anglesite and Cerrusite. It is present in ores with zinc, silver and most abundantly with copper and is extracted together with other metals.

1. Poisonous and can cause nervous disorders. 2. Very poor in electrical conductivity. 3. Malleable and can be toughened by adding antimony or metals to it. 4. Highly resistant to corrosion.

Recycling primarily of automotive batteries.

1. Lead Acid Batteries.
2. Colouring agent in ceramic glazes.
3. Projectiles in fire arms.
4. Molten Lead is used as a coolant - Eg. Lead cooled Fast Reactors.
5. As a shield from radiation.
6. Lead Glass - composing 12 to 28% lead oxide which reduces transmission of radiation.
7. Used as Electrodes in the process of electrolysis.
8. Used as Solder in Electronics.
9. High voltage power cables.
10. Added to Brass to reduce machine tool wear.
11. Lead sheets used as roofing materials.

1. Chrome Yellow: A natural pigment made of lead chromate. Because of its nature of oxidizing and darkening by exposure to air, and the lead being heavy and toxic, it is now replaced by cadmium yellow pigments.
2.Lead Dioxide: Used in Lead Acid Batteries.
3.Lead Hydrogen Arsenate: Used as an inorganic insecticide primarily against potato beetle.
4.Lead Scandium Tantallate: Used for manufacture of uncooled focal plane array infrared imaging sensors for thermal cameras.
5.Lead Styphanate: Used as a component for detonator mixtures for less sensitive explosives.
6. Lead Zirconate Titanate: Used to make ultrasound transducers, sensors, actuators etc.
7. Lead Acetate: Used in cosmetics, hair colouring products. Lead Acetate Coated paper is used to detect the poisonous gas Hydrogen Sulphide as the gas reacts with lead acetate.
8.Lead Azide: An explosive and toxic crystalline compound. Highly Sensitive and stored in water in insulated containers. It is used as a detonator in explosives.
9. Lead Chloride: Used in a big way in the chemical industry. Used in Different compositions for the manufacture of infrared transmitting Glasses, ornamental glasses, as pigment (white lead) in manufacture of white paint and in many other products.
10. Lead Chromate: Used as "Chrome Yellow" in manufacture of paints.
11.Lead Iodide: Toxic. In its crystalline form it is used as a detector material For high energy photons, including x-rays and gamma rays.
12.Lead Nitrate: A chemical compound, colourless, crystal, white powder and a strong stable oxidizer. Used as a heat stabilizer in Nylon and Polyesthers and in coatings of photo thermo graphic paper and in Rodenticides.
13.Lead Oxide: A compound used for paints, glass, vulcanization of rubber. Lead oxide when mixed with glycerine, sets to a hard water proof cement used in joining of glasses and the glass bottoms of aquariums. Used in cathode ray tube to block-x-ray emission, mainly in the nech and funnel.
14.Lead Selenide: Used for manufacture of infrared detectors for thermal imaging.
15.Lead Sulfide: Used as detection element material in various infrared sensors.
16.Lead Sulfate: Used in car batteries.
17.Lead Telluride: Alloyed with tin. Used as infrared detector material. It Occurs naturally as mineral altaite.
18.Lead Acetate: It is a lead salt of acetic acid. Used in organic chemical Industry.

1. Betterton Krol Process 2. Belts Process.

Chemical Symbol - Al; Atomic Number - 13.

Bauxite ore.

A grayish white, light, non-toxic metal with the following characteristics.1. Malleable, ductile, machinable.2. Slightly oxidizing when exposed to air.3. Good thermal and electrical conductor.4. Capable of being a super conductor with a super conducting critical Temperatures of 1.2 Kelvin.

Like Iron, Aluminium is also one of the widely used metal. It is used in..1. Automobiles, Aircrafts, Trucks, Rail Cars, Marine Vessels, Bicycles etc.2. Cans, Foils etc., 3. Windows, Doors, Carpentry fittings, Rivets, wires etc.,4. Cooking utensils.5. Cables, wires etc., 6. Powdered Aluminium for paints.7. Electronic CDs etc.,

1. Aluminium Ammonium Sulphate: Used as a mordant in water purification, sewage treatment, paper production, food additive, leather tanning etc.
2. Aluminium Acetate: A salt used in solution as an astringent ( a chemical Substance that tends to shrink or constrict body tissues).
3. Aluminium Borate: Used in the production of glass and ceramics.
4. Aluminium Borohydrate: Used as an additive to get fuels.
5. Aluminium Chloride: Used in paints as antiperspirants, in petrol refining, and in the production of synthetic rubber.
6.Aluminium Chlorohydride: Used as an antiperspirant and as an antidrotic in the treatment of Hyper Hidrosis - abnormally increased perspiration.
7. Aluminium Fluorosilicate: Used in the production of synthetic gemstones, Glass and ceramics.
8. Aluminium Hydroxide: Used as an antacid, as a mordant in water purification, in the manufacture of glass and ceramics and in the water proofing of fabrics.
9. Aluminium Phosphate: Used in the manufacture of glass, ceramics, pulp, paper, cosmetics, paints, varnishes and as a cement in dentistry.
10. Aluminium Oxide: Found naturally as Corundrum (mineral for ruby and Sapphire). Emery (hard rock powdered and used as abrasives) - sand paper, And is used in glass making. Synthetic Ruby and Sapphires are used in lasers.

Chemical Symbom - Cu; Atomic Number -- 29.

Occurs as a native mineral as sulfides - Chalcopyrite, Bormite, Covellite, Chalcolite and Carbonates - azurite, malchite and as oxides - cuprite.

Malleable, ductile, excellent conductor of heat and electricity.

Its use is enormous. However, the major areas are piping, wires, cables, electromagnets, printed circuit boards, electrical motors with coils, relays and bars switches, vacuum tubes, cathode ray tubes, microwave ovens, integrated circuits, plumbing fittings, roofing, cookwares, coins, musical instrument and so on. It is an essential nutrient to all plants and animals co factors in enzymes.

Chile and US.

Alloy of copper and zinc, in varied proportions to create a range of brasses. yellowish in color, used in decorations, statues, plumbing and electrical installations, ammunitions, kitchenware etc.,

1. Admiralty Brass: 30% zinc+1% tin+ copper.
2. Alpha Brass: 35% Zinc + copper. Also called "Princess Metal" - used in Pressing and Forging etc.,
3. Aluminium Brass: Copper+Zinc+Aluminium - to improve its corrosion Resistance.
4. Alpha Beta Brass: 35 to 45% Zinc - suitable for hot working.
5. Arsenical Brass: Contains arsenic and sometimes aluminium. Used for boiler fire boxes.
6. Beta Brass: 45 to 50% Zinc + copper - can be worked hot only. Hard and strong - most suited for casting.
7. Common Rivet Brass: 37% zinc - cheap and standard for cold working.
8. High Brass: 65% copper + 35% zinc. High tensile - used for spring, Screws and rivets.
9. Leaded Brass: With addition of lead, has excellent machinability. Low Brass: 20% zinc - golden colour - excellent ductility, suitable for Metal hoses and bellow ( a device for delivering pressurized air in a Controlled quantity to a controlled location).
10.Gilding Metal: The softest type of brass commonly available with 95%Copper and 5% zinc. Used for ammunition components.

Chemical code - Si; Atomic Number - 14.

Sand is the major source. Also available from Talc and Mica. Second most common element on earth crust. Occurs in crystalline form and in 9 different varieties., with 46 to 75% silicon and 53.25 % oxygen. Processed into two intermediate varieties - Silicon and Ferro Silicon. It is a semi conductor.

1. Used extensively in computer manufacturing.
2. Special Steels (tool) and Cast iron.
3. Aluminium Alloys.
4. Glass and Refractory materials.
5. Filler in cosmetics.
6. Pharmaceuticals.
7. Paper.            8. Insecticides.           9. Rubber.         10. Textiles.          11. Foods.          12. Paints.         13. Thermal Insulators.                       14. Ceramics and glasses.           15. Fused Silica is used as ablatives in Rocket Engines and spacecrafts.
16. Silica Fibre is used in reinforced plastics.

Jons Jakob Berzelium - 1824 - Sweden.

A common mineral in the Earth's continental crust belonging to the Silica family. Quartz goes by an array of different names and types. The most important distinction between types of quartz is that of Macro crystalline (individual crystals visible to naked eye) and the Micro-crystalline ( aggregate of crystals visible under high magnification)

Chalcedony, Agate, Onyx, Jasper, Aventurine, Tiger's eye, Amethyst, Citrine, Prasiolite, Rose Quartz, Milk Quartz, Smoky Quartz, Morion, Carnelian etc., Each of them have their own distinct color combinations.

Electronics, notably clocks.

They are stones formed with minerals in the ground identified by their glittering colours found in uncut shapes. They are precious and mostly used as jwellery. They are: Diamond, Emeralds, Sapphire, Ruby, Amethyst, Opal, Topaz, Aquamarine, Tanzanite.

Gemmology.

Presence of Chromium.

Pigeon Blood - Found normally in Myanmar.

Africa, Asia, Australia, Greenland, Kenya, Madagascar, Myanmar, Sri Lanka, Cambodia.

Month of July and the Zodiac signs of Leo and Cancer.

A highly priced gemstone occurs mostly in green colour. By weight it is the most expensive in the world. Belong to the Beryl mineral.

Trapiche.

Gachala Emerald: World's largest measuring 5 cm in uncut condition. Weight 858 carats (172 gms) found in 1967 in Columbia now with Smithsonian Institute, US.  Chalk Emerald: Columbian Emerald weighing 38 carats now with Smithsonian Institute, USA.

May and zodiac signs of Taurus and Gemini.

Naturally occurring gemstone, normally coming in Blue and occasionally in other colours like Pink, Yellow, Green, White etc.,

Due to the presence of Titanium and Iron.

Star Sapphire: with 6 rays star, when viewed with a single overhead light.

September - zodiac signs of Virgo and Libra.

A purple variety of Quartz often used as an ornament. It is believed to protect one from drunkenness.

Intense violet with red flashes called Siberian.

Brazil.

It is hydrated silcon di-oxide - comes in clear white, grey, red, yellow, green, Blue, majenta, brown and black. Red and Black are rare. May occur in any Kind of rock, mostly in limestone, sand stone, Rhyolite and Basalt.

Australia - supplies 97% of world's need. Coober Pedy, a town in Australia is the major source of opals. Lightning Ridge another town in New SouthWales is famous for Black Opals.

October and zodiac signs Libra and Scorpio.

Andamooka Opal: The most famous presented to Queen Elizabeth II in 1950 by Australia. 203 carats.
Aurora Australis: Most valuable black opal.
Halley's Comet Opal: World's largest uncut opal in Black.
Olympic Australis Opal: Reported to be the largest and most valuable Gem Opal ever found.

Silicate mineral of Aluminium and Fluorine. Comes in clear, brown, orange, Grey, yellow, green and pink.

"El Dorado" found in Brazil in 1984 - the biggest and valuable - weighing 6.2 kg - now a royal collection of UK.

It belongs to the mineral Beryl. A transparent gemstone having a delicate Blue or Torquoise color, resembling sea water. The finest comes from Russia.

Mined at the Marambaia, Brazil - weighing 110 Kg in the size of 48.5 cm X 42 cm.

March - Zodiac signs of Pisces and Aries.

Belong to the Ziosite mineral variety. Discovered in Tanzania in 1967.A popular and valuable gemstone when cut. Comes in purple to Blue in colour.

A hard round object produced by certain animals, specially Molluscs ( fish Family) and certain Oysters. It is cultivated as well as harvested. A valuable gem, comes in pure white, with a grey tint. There are Salt and Freshwater pearls. Comes in different sizes and used in jwellery. Pearl melts in vinegar. China is the largest producer of freshwater pearls.