OPAL

What is Opal?

Opal is one of very beautiful and valued stone in the world. Its unique color spectrum of such unique arrangement increase its beauty even more.

Opal is a stone of October and is an amorphous form of hydrated Silica. It is found even in cracks of different rocks commonly found with Sandstone, Limonite, Basalt or any other stone in a low temperature deposits.

Opal is not much of a hard mineral, it is situated at 5.5 to 6 Mohs hardness scale. It is found in many shades and colors from opaque, translucent, transparent or colorless to black or in dark colors.

There are common two types of Opal. Precious opal and Common opal, precious opal shows play of colors whereas, common opal shows none.

Play of colors is that when a precious opal is brought in a white light and optical effect occurs that causes flashing of different color lights on the surface of opal. It might show one color, two colors or all seven colors.

Opals are found in many countries but the precious ones are of Australia and Ethiopia. But there is lots of debate in the origin and is said that Australian opals are of greater quality.

Precious opal of perfect clarity, pattern and color can even make it of more worth then diamond, ruby, sapphire and emeralds.

One can find different patterns on the surface of opal depending on its origin.

Pinpoint or Pin fire Pattern (Small closely set patches)

Harlequin or Mosaic Pattern (Broad closely set patches)

Flame Pattern (Reddish band or streaks)

Peacock Pattern (Blue and green patterns)

Opals also have 3 types based on Host Rock and Opal combined together.

Solid Opal (Either precious or common opal it is entirely Opal without any rock attached to it)

Boulder Opal (Such opals are found attached with the host rock or within fractures of those rocks like sandstone, basalt, rhyolite etc.)

Matrix Opal (Such Opals are very much mixed within the Host rock and are commonly found in Andamooka, Australia)

 

Types of Opal

 

i) Black Opal or Dark Opal

They are preferred more than any other opal because of there dark background they show the color spectrums in such beauty that they are of much greater value then white opals.

They are of black, dark gray, dark blue even dark green in color. With each showing a unique color play.

They are said to be the rarest opals and they are found in Lightning Ridge Northern New South Wales and black opal is said the Gemstone Emblem of Australia. It’s also found in Ethiopia Wollo Province of Northern Ethiopia.

They say Honduras is the oldest place of black Opals. It has one of the famous mine in the world Tablon Mine. The black opals are extracted from volcanic black Basalt. That’s why opal has this amazing black color.

They are also found in America in Nevada, Virgin Valley Mines.

 

ii) White Opal or Light Opal

They have white yellow or cream like color and are also one of the precious opals. They have a light or white background and you can also see a beautiful spectrum of colors on its surface.

It’s a common thought that when one hears about Opal they think it’s of white color because people have not seen other colors in opal. It’s true that white, gray and green are found commonly.

White or Light opals are found in many countries but, early opal where mined in Australia. Most valued ones are found in Copper Pedy & Mintabee, South Australia.

Yet again beautiful milky white to white matrix Opals are found in Honduras & Mexico.

America is also one of those countries rich with Opals. Royal Peacock Opal Mine & Bonanza Opal Mine in Nevada.

 

iii) Crystal Opal & Water Opal

Crystal opal is transparent to semitransparent and is and is a very beautiful form of opal. It has a clear background and it show a beautiful spectrum when light hits its surface.

Brighter & more the colors of the spectrum will increase the value of the opal. Though red, Green and blue dominate in the colors when seen in different angles under light.

Whereas, water opal might not show them spectrum if it does it will be weak color appearance.

They are found in abundance in Australia in Copper Pedy & Mintabee, America, Mexico & Ethiopia.

 

iv) Pink & Blue Opal

These are the forms of common opals they do not show the color play and are opaque.

Pink Opals are more like whitish pink or lilac colored and are used in different jeweler.

Blue Opals are more of a pastel like blue appearance, even a blue green shade are found in it. They are also famous with the name Peruvian Opals

Pink and Blue Opals are mostly found in Peru, Oregon & Thailand.

 

v) Fire Opal

Fire opal is an opal which is either transparent or translucent. It often shows bright color spectrum. It is beautifully cut in cabochons and are valued.

The often are found in rhyolite matrix. They have different color and shades red, Orange or Yellow.

They are found in Mexico famous for fire opal and also known as Mexican Opal due to its abundance in this country. It has extinct volcanic mountain from where they are extracted.

Opals are found in state of Queretaro & Magdalena. Famous is Pata de Gallo Mine northwest of Madalena.

They are also found in Royal Peacock Opal Mine & Bonanza Opal Mine in Nevada, America.

Very unique fire opals are also found in Brazil, near Campos Borges in the South Brazilian State of Rio.