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A cabochon is a stone that is cut with a highly polished rounded top with no facets, and a flat or slightly domed base. Before the art of faceting was developed, most gemstones were fashioned into cabochons, though some were intricately carved as well. The cabochon is the most traditional of all gemstone forms.
When the horizontal cutting wheel was invented in the late 15th century, it became possible for the first time to create gemstones with complex faceting designs. The fascination with geometry and reflected light during the Renaissance accelerated the development of a sophisticated lapidary art. Yet, even once the technology and skill was available to facet gemstones, cabochons were still produced. They continue to be very popular today. What is the reason for the enduring popularity of this simple design?
In some cases, gems are cut as cabs because they have special properties that are displayed only in the cabochon form. Examples are gems that display asterism (the star effect), chatoyancy (the cat's eye effect), iridescence (e.g., opal) or adularescence (e.g., moonstone).
Most gems that are opaque rather than transparent are cut as cabochons rather than faceted. Lower grade translucent material in gemstone varieties such as sapphire and ruby are also cut as cabs. If the gem material has good color but is not sufficiently transparent or clean to be faceted, it can still be shaped and polished into a very attractive cabochon. It is also common to cut softer stones as cabs, since minute scratches show much less on a cabochon than on a faceted stone.
Aside from these practical considerations, a cabochon exemplifies two of the properties that we treasure in colored gems. The first is that cabochons are pure color. While most cabs have an attractive luster, they don't obscure color with brilliance. Secondly, cabochons are as close to the natural material as you will find in a gemstone. They have only been shaped and polished in a simple way. When you see a large carnelian or lapis lazuli set in jewelry, you are looking at a gemstone that could have been worn by one of our ancestors two thousand years ago.
We stock cabochons in more than 80 different varieties, in almost every possible color. They range in size from half carat opal and chrysoberyl cat's eye gems to star rose quartz stones weighing over 600 carats. A number of varieties are quite rare, such as ammolite, hemimorphite, smithsonite and sugilite. In total, we have over 5,000 cabochons in our inventory.
Rutile (or rutilated) quartz is clear or smoky quartz with inclusions of rutile. Rutile is the mineral name for natural crystals of titanium dioxide. The rutile needles form lovely patterns like miniature sculptures. Every stone is quite unique - some have delicate hair-like intersecting needles; others have dense clusters of thicker needles. Very large transparent stones that are free of defects are rare, so this huge but quite perfect rutile quartz from India counts as a true collector's item.
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Happy gem hunting,Your friends at GemSelect
- First Published: June-01-2010
- Last Updated: October-29-2014
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