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Unusual black chalcedony geode and other anomalies

Unusual black chalcedony geode and other anomalies

By /October 26, 2023 /0 comments /Cut Rocks

This is only the second black geode I have encountered on The Carver. This is dense black chalcedony, not basalt. Other photographs shown here are of the cabs which I cut from this black geode. Rock #5343I have never before encountered pitch black chalcedony in a Carver geode. Chalcedony is a micro-crystalline quartz (silica) common in many agates. It can be many colors but is most often translucent or transparent. Pitch black coloration is, from my experience, very rare. Click on the images below to view enlarged versions of this examples. Rock #5336 Rock #5248 Rock #5241 One stone yielded a slab that I turned into this fancy-cut designer free form cab (Rock #5325), as well as stone #5258 below. Rock #5325 Rock #5258 Last but not least. . . This small flat-topped cab features a crystal filled vug and the ‘fill tube’ (term likely not geologically correct) all from […]

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Brecciated Lava Agate

Brecciated Lava Agate

By /January 15, 2022 /0 comments /Geology

This stone was cut as a geological oddity, rather than as a gemstone. I doubt it will ever be set as part of a piece of jewelry. First, you notice three jagged shards or pieces on the left side of the rainbow shaped stone. These shards are from hardened lava that was broken and fell into a crack in the lava surrounding the shards. The lava, which was initially molten and then hardened, was at some later point in time broken by tectonic forces or by volcanic explosion or lifted by rising magma. The crack and the shards were later (How much later, you ask? How the hell would I know?!!) filled in by a silica solution or silica gel that subsequently crystallized and formed the brown material surrounding the three shards. The surrounding material is chalcedony (a micro-crystalline quartz structure). Chalcedony is a common material in many agates and […]

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