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How Are Tumbled Stones Made?
Tumbled stones are made in a machine known as a rock tumbler. The most commonly used rock tumbler is a rotary machine that turns a barrel containing the stones, along with abrasive grit, and water, for days and weeks at a time. As the rocks tumble in the barrel, the grains of abrasive grit get caught…
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What Materials Are Used to Make Tumbled Stones?
The most popular materials used for making tumbled stones are attractive and colorful rocks and minerals that have a Mohs hardness between 5 and 8. These materials are generally durable and accept a good polish. Some of the most commonly tumbled materials are listed below. Varieties of Chalcedony: Varieties of Crystalline Quartz: Minerals: Rocks: Fossil Materials:
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Tumbled Stones:
Rough rocks transformed into smooth, shiny, colorful works of natural art! What Are Tumbled Stones? Tumbled stones are small, rounded, brightly polished pieces of rocks and minerals. They are made by placing rough rocks in a machine known as a rock tumbler, which tumbles them until their edges and surfaces are smooth and polished. They are also known as…
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What’s the Future of Ethiopian Opals?
The future is very bright for Ethiopian opals. They are becoming much more visible in the gem and jewelry market, and the gem-buying public is becoming aware of them. All of this has occurred without a major mining company or jewelry brand spending millions of dollars to promote them. They occur in a variety of…
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Ethiopian Opal Treatments
Many Ethiopian opals are sold in their natural state, and some are treated. Their porosity makes them good candidates for dye, smoke, and sugar/acid treatments. All of these treatments, when disclosed, reduce the price of the opal to much less than natural opal with the same appearance. When undisclosed they can deceive inexperienced buyers and…
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Hydrophane Opals
Many of the opals mined in Ethiopia, especially from the Welo deposits, are hydrophane opals. “Hydrophane” is a name used for a porous opal that has the ability to absorb water. A change in color or transparency often accompanies the water absorption. These opals typically have a lower specific gravity than other types of opal…
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Welo “Precious Fire Opals”
Much of the opal produced from the Wollo Province has an orange, yellow or reddish body color along with play-of-color. The orange, yellow or reddish body color meets the definition of a fire opal, and the play-of-color meets the definition of a precious opal. Meeting both criteria, these opals could be called “precious fire opals.” The orange…
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A Short History of Ethiopian Opal
Precious opal mined in Ethiopia began entering the gem and jewelry market in 1994. This opal originated from a discovery made in the Menz Gishe District in the northern part of the Shewa Province. Opal from this area occurs in a wide range of body colors. Much of the opal has a brown, red, or…
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Ethiopian Opal
The New Opal Heavyweight: Australia has been the dominant force in the opal market for over 100 years. During that time as much as 95% of the worldwide opal production has been mined in Australia. Today, Ethiopia is on its way to becoming the second heavyweight in the opal market. A small discovery in 1994 put Ethiopia on the worldwide…
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Diopside:
Diopside is a beautiful and relatively inexpensive gemstone that is occasionally seen in commercial jewelry. Specimens that contain chromium have a brilliant green color. Many people who see chrome diopside in a jewelry display initially think that it is an emerald. Then they are surprised to learn it is a gem they have never heard about. Diopside is a gem…