Geodes

Geodes are nodules with a hollow cavity filled with crystals. They are a fascinating geological wonder. From the outside, they appear as any common, ugly rock, but when broken open they reveal a charming display of crystals. Practically all geodes are composed of Quartz. The crystals can be microscopic or can be quite large. When it occurs in crystals not visible to the human eye, it is known as a Chalcedony Geode ( Chalcedony). Most geodes are surrounded by a banded layer of Agate around the hollow area, giving the geode a beautiful look when polished. The Agate layer can be quite thick, and in certain geodes, it completely fills the hollow cavity, leaving a solid nodule incorrectly called "Agate Geode". Geodes are limited to a small number of localities. However, in those localities, they occur in great abundance. Geodes of all shapes and sizes occur, and fine specimens can be purchased almost anywhere. Most specimens look ugly unless sliced evenly and polished. Some geodes are artificially dyed. Such examples do not find favor with the serious collector, who is usually able to discern natural material from dyed. Most electric blue, bright green, and flashy red specimens are artificially dyed.

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