Month: March 2020

Agate “Vugs”

Agate “Vugs”

Some, but not all, agates contain “vugs,” tiny voids often filled with quartz crystals.  They are a sort of miniature geode.  The crystals when present are usually very petite (sometimes microscopic). Note that two of the three vugs pictured in the image below have visible quartz crystals.  Some lapidists view vugs as imperfections to be avoided when cutting a stone.  I, however, love to include vugs when cutting cabochon. I like to see the sparkle that often emanates from the vug when a tiny crystal catches a ray of light. Including a vug in a cab adds beauty, uniqueness, and perhaps, as some believe, mystical powers.  I do not know the technical name for the type of agate shown. In fact, many agate types are unnamed or have local names which have been applied to them.  If you would like to name this type of agate, let me know what […]

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Chaos vs. Orderly Perfection

Chaos vs. Orderly Perfection

Formed within tuff, a white volcanic ash which has been compressed and hardened, over millions of years, to a very limited extent, is what I describe as a “chaos agate.” That is not an official agate designation, however.  Apparently, a hodgepodge of mineralization mixes with and in a silica-rich solution which subsequently hardens within the tuff. Since this type of agate forms in a ashy mass, the agate has no orderly shape or form. Chaos Agate On the other hand, here is the orderly perfection  of a cabochon from a cross section of a geode.  If you follow this website, you are probably aware that the orderly shape is from the gas bubble in the lava in which geodes form.  A silica-rich solution and mineralization fill the gas bubble and create the geode’s shape.  The gas bubble fills with silica and mineralization through the ‘fill tube,’ so called, which is […]

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