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What Is Tiffany Stone?
“Tiffany stone” is a trade name used for a purple, blue and white gem material that can be cut and polished into beautiful beads, cabochons and tumbled stones. Geologically, Tiffany stone is a rock composed primarily of fluorite with smaller amounts of opal, calcite, dolomite, quartz, chalcedony, bertrandite and other materials. Other names used for Tiffany stone are “opalized fluorite,” “ice cream stone,” and “bertrandite.” A…
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Not Really “Wood”
A material found in the Catahoula Formation of Louisiana, Mississippi and Texas is widely known as “petrified palm wood.” However, palm plants really don’t produce “wood.” Instead their trunk is made up of parenchyma, a fibrous support material that is surrounded by hollow tubes of the vascular structure known as xylem and phloem. These tubes transported…
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Collecting Petrified Wood Legally
Collecting petrified wood can only be done on private property where permission has been obtained from the landowner, or on limited tracts of government lands where small quantities are allowed to be collected for personal use. Before you collect, get permission and collecting rules from the owner of private property or from the government agency…
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Lapidary Uses of Petrified Wood
Petrified wood is often used in lapidary work. It is cut into shapes for making jewelry, sawn into blocks to make bookends, sawn into thick slabs to make table tops, and sawn into thin slabs for clock faces. It can be cut into cabochons or used to make tumbled stones and many other crafts. Small pieces of petrified wood…
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Types of Silicified Wood
Some of the best specimens of petrified wood have been preserved by silicification. Two forms of silicification are common. The most abundant is wood that has been replaced and infilled by chalcedony (sometimes called “agatized wood”). The other form is wood that has been infilled and replaced by opal (usually called “opalized wood”). Both of these varieties…
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Other Petrified Wood Localities
Petrified wood is not rare. It is found in volcanic deposits and sedimentary rocks at many of locations worldwide. It is sometimes found where volcanic activity covered plant material with ash, mudflows or pyroclastic debris. It is found where wood in sedimentary deposits was replaced by minerals precipitated from groundwater. It is especially abundant around…
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Petrified Forest National Park
The most famous locality for observing petrified wood is Petrified Forest National Park near the community of Holbrook in northeastern Arizona. About 225 million years ago, this area was a lowland with a tropical climate and covered by a dense forest. Rivers flooded by tropical rain storms washed mud and other sediments into the lowlands. Enormous…
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What is Petrified Wood?
Petrified wood is a fossil. It forms when plant material is buried by sediment and protected from decay due to oxygen and organisms. Then, groundwater rich in dissolved solids flows through the sediment, replacing the original plant material with silica, calcite, pyrite, or another inorganic material such as opal. The result is a fossil of the original woody material that…
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Lab-Created Yellow Diamonds
Many of the first attempts to produce diamonds in a laboratory resulted in diamonds with a yellow color. Consider that one nitrogen atom per several thousand carbon atoms can impart an obvious yellow color in a diamond. Then consider that nitrogen is the most abundant gas in the air of the laboratory. It was very…
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Yellow Diamonds and Treatment
Yellow diamonds have been produced by treating brownish diamonds. These treatments include HTHP (high temperature, high pressure), irradiation, annealing and coating. Some of these treatments can be reversed or altered if the diamond is subjected to heating during jewelry repair. Coatings are often thin layers of silica applied to the surface of the stone. These…