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Natural Opal

Opal is a poorly crystalline or amorphous hydrous silica that is compact and vitreous and most commonly translucent white to colourless. Precious opal reflects light with a play of brilliant colours across the visible spectrum, red being the most valued. Opal forms by precipitation from silica-bearing solutions near the Earth's surface. Electron microscopy has shown that many opals are composed of spheres of tens to a few thousand angstroms in size that are arranged in either hexagonal or cubic close packing. The spheres are composed of hydrous silica that may be either almost cristobalite-like, tridymite-like, mixtures of both, or random and nondiffracting. The specific gravity and refractive index are lower than those of pure silica minerals. The play of colours in precious opal arises from the diffraction of light from submicroscopic layers of regularly oriented silica spheres. When heated, opal may lose as much as 20 percent of its weight of water, fracture, and then crystallize to one of the silica minerals described above.


  • There are 93 Opal gemstones available at Multicolour.com
  • Opal(s) are organized in the following categories: Single,  gemstones.
  • Our most expensive Opal is USD 1402.20 and largest Opal weight is CTS 58.36.
  • Our cheapest Opal is USD 69.00 and smallest Opal weight is CTS 1.87.

Find your Opal

Our Opal(s) are available in various shapes, sizes and colors. 93 Opal(s), too many to look through? You may select any combination of search options. Colors grade into each other and you can search for more than one color at once. For a better selection, try selecting two or three colors, -- your first choice plus the two closest colors.

Shape Length (mm) Width (mm)
Category Weight (cts) Price (USD)
Color range
orangy yellow
yellow

Opal Profile

Color information: White, green, blue, black, red, orange, violet, pink, grey, yellow.
Refractive Index: 1.44-1.46
Chemical Composition: SIO2nH2O
Hardness: 5.5 - 6.0
Density: 2.65 - 3.00
Crystal Group: Amorphous
Ocurrence: Czechoslovakia, Mexico, Honduras, Australia, Brazil, Tanzania.
Sign of the Zodiac: N/A
Month of the year: N/A
Opal
Opal usually contains 4 to 9 percent water, but lower and much higher values have been observed. The contents of alumina, ferric oxide, and alkalis are variable but may amount to several percent in light-coloured opals and more if pigmenting minerals are also present. Precious opal has been synthesized. Opaline silica is a friable hydrous silica found near hot springs and geysers.

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Finest gems/
Tourmaline Pair
From our finest gemstones collection
Tourmaline Pair Oval Eye clean
Size: 9.20 X 7.60 MM
Weight: 5.060 CTS
Shape: Oval
Clarity: Eye clean
Usually ships within 24 hours
OUR PRICE
USD 3758.40
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Deal of the Day/
Color Change Garnet Single
limited time offer, ref# YCG268ai
Color Change Garnet Single Heart Moderately to Heavily included
Size: 5.10 X 5.50 MM
Weight: 0.680 CTS
Shape: Heart
Clarity: Moderately to Heavily included
Usually ships within 24 hours
10 % OFF, YOU SAVE 4.08 USD
NOW ONLY
USD 36.72
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Today’s Trade/
Best Selling Gems:
Sapphire Sapphire
691 Sapphire ’s available
Browse gems | Learn More
Spinel Spinel
380 Spinel ’s available
Browse gems | Learn More
Tanzanite Tanzanite
227 Tanzanite ’s available
Browse gems | Learn More
Alexandrite Alexandrite
278 Alexandrite ’s available
Browse gems | Learn More
Zircon Zircon
272 Zircon ’s available
Browse gems | Learn More
Gemstone Variety: Hits Index
Going Down Sapphire -374 +-0.0%
average price USD 356.54 per item
Going Up Alexandrite +1207 +0.1%
average price USD 2693.57 per item
Going Down Tsavorite -246 +-0.0%
average price USD 216.99 per item
Going Down Diamond -293 +-0.0%
average price USD 12105.67 per item
Going Down Spinel -550 +-0.0%
average price USD 534.42 per item
See more real time gem reports.
Exchange rates to USD
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Euro 0.938
United Kingdom Pounds 0.818
Japan Yen 114.743
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Gem Library /
Gems Legend and  Lore This month birthstone: Citrine, Topaz
More from the Gem Library about Birthstones.
Sagittarus Sagittarius
November 22 – December 21
Mutable Sign. Goes at a great gallop. Your zodiac stone...more

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