Opal Picture guide showing the major categories
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This guide will help identify the different types and show how to recognize them. We first start with Lightning Ridge Black Opal.
Black Opal when found with a natural black or dark background is called ‘black opal’. This background can range from pitch black to grey giving the stone are dark-ish appearance and when seen from the top is opaque [Not allowing light to pass through].
It is the dark background which allows the brilliant colors. Black opal can be any color. The specimen pictured has a dominant color of blue. It is approximately 1-1/2 cm in length.[This particular stone has now sold].
Dark Opal Dark opal is found on most fields. It’s background color ranges from grey to near black.. Black opals are in the same family as Dark opals (also opaque- not allowing light to pass through). They are just dark opals with a blacker background.
As the background of this stone becomes lighter and grayer it gets closer to light opal and its sometimes difficult to decide whether a dark opal should be categorized as dark or light. It’s often in the eye of the beholder.
The Difference between Lightning Ridge and Boulder black opal
A form of black or dark opal although it must be said that there are light colored boulder opals as well as dark and black. Boulder opals are still attached to the mother rock that they were born in.
The latest Opal Nomenclature identifies Boulder opal as being black opal as well. The term ‘black opal’ does not identify the origin of the stone but rather its appearance.
Boulder opals often have the same dense color as Lightning Ridge stones and hence are placed in the category of Black Opals. Most (but not all) boulder opals have flat tops and stones from Lightning Ridge are often high domed. However Boulders often have more denseness and brilliance than gems from Lightning Ridge at a more competitive price. Boulder gems often have ironstone inclusions in the foreground which reduces their price but in the opinion of many, add to the personality of the stone. Video of high grade black boulder opal
Yowah opal: This is a variety of boulder opal that comes in the form of small ‘nut-like’ lumps that, when cut, have layers of ironstone mixed with color and sometimes, rarely, a kernel of precious opal. These beautiful pieces are collectors items, each one totally unique in the world. examples shown here.
From the Quilpie opal fields in western Queensland. Often these specimens are left exactly as they have been found in the ground and are used for display purposes in people’s gemstone collections.
Because Boulder opal, as far as we know, is only found in one place on the planet, that is Queensland, Australia, you can imagine that specimens like this are in high demand
Split faced boulder As the title indicates, this is a boulder opal that has been split along the vein of color, resulting in two identical pieces, one concave and one convex.
This amazing natural appearance results in an identical pair that can be used as earrings if they are small enough or for specimen collectors. This pair comes into the second category as they would be a bit much to wear on the ears.
Opal Picture guide: Boulder opal Abstracts
(this is our terminology and is not an official description) but we feel that it best describes the endless varieties of these unusual opals often call ‘fun stones’, an expression that really doesn’t tell you anything about what they are.
Take a look here at our gallery of picture stones, if you have not already done so.
Opal Picture guide: Opal Carvings
As the term suggests, opal, both boulder ironstone and white or black opal is often used to carve figurines
have received this name because from time to time as an opal is opened up from inside a boulder opal (particularly) or a black opal, something comes out that amazingly looks like an item from nature, such as an animal, a rainbow, a bird, a fish, etc. the variety is endless.
White Opal A solid opal with an opaque [non see-through] light background. White opal is often called milk opal because of its light appearance.
Crystal opal is of the same family but it is more translucent and sometimes transparent whereas the color of white opal is on the surface.
This type of opal can appear in all fields but Coober Pedy is famous for it. Some people prefer the more delicate, less dramatic appearance of the white opal. Crystal opal holds a certain fascination because the eye is able to look deep into the stone and gaze at its internal mysteries.
Light Opal crystal (sometimes called ‘jelly’ opal) This type of opal does not have a dark or black background and hence has a more delicate, less dramatic appearance because the surface is not opaque and the light is able to shine either right through the stone, or at least INTO it
Dark Opal Crystal This is when the crystal opal has a darker appearance within it’s body. Dark opal describes the in-between status of the stone.
Its not white opal and its not black opal, its a progression between the two types. This illustrates the marvelous complexity of the opal stone and the difficulty we have in arriving at accurate definitions.
When its all boiled down, opal is at the mercy of the beholder. What appeals to one person will not be as appealing to another. But isn’t that what life is all about? We are open to choices.
Andamooka Painted Lady This stone is what could be called the South Australian ‘boulder opal’. Not because it is boulder ironstone but because it comes in large chunks like boulder and is often split out of the ground along the lines of color.
It is pale in appearance but sometimes has some dark potch in the background of the color which gives it an attractive feature and is another example of a type of black opal because any opal with a black background is in this category.
The previously described opals are all naturally formed. Mosaic opal is created by a skilled artist who assembles the small pieces of natural opal into a mosaic pattern.
These Slivers of genuine opal are assembled into an irregular tiled pattern with rivers of black potch framing each unique opal tile.
Mosaic opals make stunning stones for all types of jewelry and allow the jeweler to include a wide range of colors within an affordable piece.
This assembly of small opal pieces is not to be confused with the Harlequin opal which features squarish spangles of color appearing naturally in the opal face. It is the rarest and most expensive opal.
Matrix Opal This type of opal comes in two categories namely:
Boulder Matrix which is a completely natural stone made up of boulder ironstone with flecks of precious opal showing throughout the stone.
These come in endless varieties from Winton to Yowah and Koroit. Usually found in association with boulder opal which tends to have larger faces of opal found in veins, whereas the matrix opal color is scattered throughout the body of the mother ironstone.
These amazing opals come in such variety and are much sought after by opal collectors.
Andamooka Matrix is a natural stone that, when it comes out of the ground is quite pale in appearance. By impregnating it with a black carbon process, the stone turns dark and when cut and polished, takes on the appearance of black opal.
However, keep in mind that even though the stone is natural, there is a man made treatment involved which has to be stated at point of sale.
Are natural opals that have been assembled with a dark or black background that is cemented in place so that the stone takes on the appearance of black opal.
Opal is one of the only stones that can cater both for someone who can afford a large amount of money or someone who only has a few dollars.
Composite opals such as doublets, triplets, and mosaics are still real opals and can be stated as such with the qualification that they have been assisted by man with the installation of a dark backing, or in the case of triplets, with a crystal protective cap as well. for further general research on gemstones click here
We hope that you have benefited by this picture guide to the opal.