Alexandrites

• Smithsonian museums' Alexandrite, the largest cut alexandrite weighing 65.08 carats.

Opal

Opal

Opal is an amorphous form of silica related to quartz, a mineraloid form, not a mineral. 3% to 21% of the total weight is water, but the content is usually between 6% to 10%. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most...

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• The Andamooka Opal
  Andamooka Opal
  The Andamooka Opal is a famous opal which was presented to Queen Elizabeth II in the 1950s on the occasion of her first visit to Australia. It was discovered in Andamooka, South Australia, an historic opal mining town....
  
  , presented to Queen Elizabeth II, also known as the Queen's Opal
• The Aurora Australis Opal, considered to be the most valuable black opal
• The Black Prince Opal, originally known as Harlequin Prince
• The Empress of Australia Opal
• The Fire Queen Opal
• The Flame Queen Opal
  Flame Queen Opal
  The Flame Queen Opal is perhaps the most famous of all opals. It is the best-known example of “eye-of-opal”, an eye-like effect created when opal in-fills a cavity....
  
  
• The Flamingo Opal
• The Halley's Comet Opal
  Halley's Comet Opal
  The Halley's Comet Opal is the largest uncut black opal in the world, according to the Guinness Book of World Records. It is so named because it was unearthed in 1986, a year when Halley's Comet could be seen from Earth. It is the third largest gem grade black opal ever recorded, the largest one...
  
  , the world's largest uncut black opal
• The Jupiter Five Opal
• The Olympic Australis Opal, reported to be the largest and most valuable gem opal ever found
• The Pride of Australia Opal, also known as the Red Emperor Opal
• The Red Admiral Opal, also known as the Butterfly Stone

Pearl

Pearl

A pearl is a hard object produced within the soft tissue of a living shelled mollusk. Just like the shell of a mollusk, a pearl is made up of calcium carbonate in minute crystalline form, which has been deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other...

• Arco Valley Pearl
  Arco Valley Pearl
  The Arco Valley Pearl is a white natural blister baroque pearl with pink and yellow overtones. It measures 79 x 41 x 34 mm. It is the largest natural pearl outside a museum and the second biggest ever...
  
  
• The Pearl of Lao Tzu
  Pearl of Lao Tzu
  The Pearl of Lao Tzu is the largest known pearl in the world. It is not a gem-quality pearl, but is instead what is known as a "clam pearl" or "Tridacna pearl" from a giant clam. It measures 24 centimeters in diameter and weighs 6.4 kilograms...
  
  
• La Peregrina
• Satlada
  Satlada
  Satlada is a seven stringed pearl necklace typically made in Basra. It has 465 pearls embedded in it. It can also be set with emeralds, diamonds and rubies.Some of the pearls are so large they look like small eggs, or outsized peas....
  
   - A seven-stringed pearl necklace of the Nizams
  Jewels of The Nizams
  The Jewels of the Nizams of Hyderabad State are the largest and richest collection of jewels in India. The jewels belonged to the Nizams. After merger of their kingdom, the Nizam and his heirs were barred by the Indian government from removing the collection, claiming it was a national treasure...
  
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Ruby

Ruby

A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum . The red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires...

• The DeLong Star Ruby
  DeLong Star Ruby
  The DeLong Star Ruby, a oval cabochon star ruby, was discovered in Burma in the early twentieth century. It was sold by Martin Ehrmann to Edith Haggin DeLong for US $21,400, who donated it to the American Museum of Natural History in New York in 1937....
  
  
• The Hixon Ruby Crystal
• The Midnight Star Ruby
• The Neelanjali Ruby
  Neelanjali Ruby
  The Neelanjali Ruby, at 1,370 carats , is the world's largest double-star ruby.A ruby is known as a star ruby if it contains an asterism in the gem. The Neelanjali Ruby is the world's largest star ruby with a 12 point asterism, which is commonly denoted as a double-star ruby. The ruby belongs to G...
  
  
• The Rajaratna Ruby
  Rajaratna Ruby
  At , the Rajaratna Ruby is one of the world's largest ruby crystals, but is more of specimen than gem quality. An crystal exists and there is a piece from Myanmar. The "Chaiyo Ruby" is another large example, weighing ....
  
  
• The Rosser Reeves Ruby
  Rosser Reeves Ruby
  The Rosser Reeves Ruby, Weighing , is one of the world's largest and finest star rubies. This Sri Lankan stone is renowned for its great color and well-defined star pattern. Advertising mogul Rosser Reeves, who donated the piece to the Smithsonian in 1965, carried it around as a lucky stone,...
  
  

Sapphire

Sapphire

Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...

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• The Logan sapphire
  Logan sapphire
  The Logan sapphire is a flawless specimen from Sri Lanka, a cushion-cut stone which possesses a rich deep blue color and is the second largest sapphire known, weighing 422.99 carats .The Logan sapphire is named after Mrs...
  
  
• The Queen Marie of Romania Sapphire
• The Ruspoli Sapphire
  Ruspoli Sapphire
  The Ruspoli Sapphire, also known as the Wooden Spoon-Seller's Sapphire and the Great Sapphire of Louis XIV, is a 135.8 carat blue sapphire nearly without flaw. It possesses only six facets and is known for its distinctive lozenge shape....
  
  
• The Star of Asia Star Sapphire
• The Star of Bombay
  Star of Bombay
  The Star of Bombay is a 182 carat cabochon-cut star sapphire originating from Sri Lanka. The violet-blue gem was given to silent film actress Mary Pickford by her husband, Douglas Fairbanks. She bequeathed it to the Smithsonian Institution....
  
  , given to Mary Pickford
  Mary Pickford
  Mary Pickford was a Canadian-born motion picture actress, co-founder of the film studio United Artists and one of the original 36 founders of the Academy of Motion Picture Arts and Sciences...
  
   by Douglas Fairbanks, Sr
• The Star of India
  Star of India (gem)
  The Star of India is a 563.35 carat star sapphire, one of the largest such gems in the world. It is almost flawless and unusual in that it has stars on both sides of the stone...
  
  , the largest and most famous star sapphire in the world
• The Stuart Sapphire
• The Black Star of Queensland
  Black Star of Queensland
  Black Star of Queensland is a gem. It is the world's largest star sapphire. It was discovered in Australia in the 1930s.The gem has been involved in several ownership disputes....
  
  , with a weight of 733 carats (146.6 g)

Spinel

Spinel

Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...

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• The Black Prince's Ruby
  Black Prince's Ruby
  The Black Prince's Ruby is a bead-shaped spinel weighing roughly , approximately the size of a chicken egg. It is currently set in the cross pattée above the Cullinan II in the front of the Imperial State Crown...
  
  , actually a spinel mounted on the Imperial State Crown
  Imperial State Crown
  The Imperial State Crown is one of the Crown Jewels of the United Kingdom.- Design :The Crown is of a design similar to St Edward's Crown: it includes a base of four crosses pattée alternating with four fleurs-de-lis, above which are four half-arches surmounted by a cross. Inside is a velvet cap...
  
  
• The Samarian Spinel
  Samarian spinel
  The Samarian Spinel is a spinel gemstone that is the largest of its kind in the world. It is part of the Iranian Crown Jewels.-Origins:It, together with a smaller spinel, were captured by the Persian King Nader Shah during his 18th century conquest of India...
  
  , the world's largest spinel
• The Timur Ruby, believed to be quartz until 1851

Topaz

Topaz

Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO42. Topaz crystallizes in the orthorhombic system and its crystals are mostly prismatic terminated by pyramidal and other faces.-Color and varieties:...

• The American Golden Topaz
  American Golden Topaz
  The American Golden Topaz, a 172-faceted topaz weighing , is the largest cut yellow topaz in the world, and one of the largest faceted gems of any type in the world. Originating from Minas Gerais, Brazil, it was cut by Leon Agee over a period of two years from an 11.8 kg stream-rounded...
  
  , the largest cut yellow topaz weighing nearly 23000 carats (4.6 kg).
• The Chalmers Topaz
  Chalmers Topaz
  The Chalmer's Topaz is a topaz gem weighting 5,899.5-carats located in Chicago, Illinois' Grainger Hall of Gems, in the Field Museum of Natural History. It was named for former Field Museum trustee William J. Chalmers and is one of the largest cut topaz gems in the world....
  
  , a 5899.5 carats (1.2 kg) cut topaz.