Month: September 2022

Yellow Fortification Agate Geode Cabochon

Yellow Fortification Agate Geode Cabochon

Rock #4876Click to enlarge This is a beautiful cab cut from a cross cut slab from a Carver geode. The crystal-lined geode center sparkles in the center of the yellow fortification agate. The sagenitic material (green and brown stuff) along the top edge of the stone indicates that this was the bottom of the geode when formed in a lava gas pocket. The sagenitic material likely fell off the inside top of the gas bubble pocket to the bottom of the gas bubble pocket where it was encapsulated by bluish agate (silica) as it filled the gas bubble pocket. See photo 4877 below which is the same stone photographed with the sagenitic material on the bottom of the stone as it would have been formed. Rock #4877Click to enlarge

Lava Breccia in Agate Matrix

Lava Breccia in Agate Matrix

What a unique and interesting cab! Close-up shows lava shard at top centerClick on the image to view an enlarged version Another cab from the same stoneNote the same lava shard (top center) These two cabochons were cut from a single stone. The lava shard (top center in both stones) shows their common origin. Above is another agate breccia with banded agate (top and lower right shards) with a lava shard in the lower center of the stone. Note the eye agate on the left center edge of the cut stone. While this stone is not pretty, it sure is interesting—at least to an old rocker like me.

Mystery Crystals Appear AGAIN:  New information from new specimen

Mystery Crystals Appear AGAIN: New information from new specimen

My June 2021 blog posting identified long petite black mineral crystals which had not been seen by me before in over 14 years of cutting thousands of ‘Carver agate field’ geodes. The June 2021 find was the only exemplar I had seen–until now! The new specimen photos below offer better views of the crystals. Interestingly, the crystals in both specimens appear to have grown out of and through an otherwise perfectly formed clear crystal lined geode center. The crystals, while appearing very fragile, are actually quite robust, being resistant to damage from washing the stone (after being cut open) to remove cutting oil, and from polishing on a bull wheel grinder. There is tremendous vibration generated from using the bull wheel, which turns very high RPMs and utilizes a 100 grit belt as part of the process. So, the crystals are not fragile or water soluble, but are very rare […]

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