

This beautiful rock has probably been dyed on the outside, as such vibrant blue colors are not often seen in nature (although they are, sometimes). But it is a lovely color, definitely! This is the outside of a geode, a rock with a hollow center in which small crystals have grown by mineral-rich water seeping into it through small cracks. Most geodes have clear quartz crystals inside, but purple amethyst can also be found as well as celestite, calcite, and other minerals.
The following photo shows the view into the vug (the hollow cavity) of this geode, and bright spots of reflected light can be seen. Extremely small crystals such as are found in geodes are called druze (rhymes with "ooze").
Also, with a little imagination, the opening of the vug mimics the outline of a kittycat, so @enginewitty thought this geode was perfect for me... π

The following 30-second video shows the geode being slowly turned in my hand, and the play of light off the druzy crystals makes teeny flashes of light, like glitter:
video by me
Geodes come in all sizesΒ β and, as with most things, there are many small ones, but the larger sizes are more rare. Those the size of baseballs are more rare than this size, and softball-sized geodes are more rare still. I found two sources, both of which claim to be the "largest geode in the world"Β β I can't be certain which source is accurate at truly being the largest, but both are amazing, indeed. The one that, perhaps, is the larger of the two has dimensions up to 35-feet (10.668 m) in diameter and is called Crystal Cave on South Bass Island in Lake Erie, off the shore of Ohio in the US. The other is PulpΓ Geode in Southern Spain, described as being "a 390-cubic-foot (11 cubic meters) cavity about the size of a cement mixer drum." [source]

SOURCES Β Β Β 1 Geology.com: Geodes Β Β Β 2 Wikipedia: Geode

Barbeque & Amethysts β’ Salt Lamps β’ Trilobite β’ Arrowhead
Garden Quartz, freeform β’ Granite Quarry β 2 β’ Apophyllite
Rocks from Space! β’ Quartz Rock: Raw versus Polished
Chrysocolla β’ Tourmaline β’ Bornite β’ Goethite β’ Small Quartz Crystal
Smoky Quartz β’ Tibetan Quartz β’ Amazonite Beads β’ Zoisite
Rutilated Quartz β’ Garnet β’ Amazonite Sphere β’ Lapis Lazuli Mala
Amethyst Point β’ How Rocks Get Their Color β’ Red Jasper
Ring, Ring! Amethyst Calling! β’ Lapis Lazuli β’ Turitella Agate




12-Nov-2019
Return from Kitty Geode to πππ₯π₯πͺ's Web3 Blog