At the Rock and Fossil ID day people brought in some interesting finds. Two in particular caught my attention. First was a concretion containing ammonite & clam fossils brought in by Mary Alderson of Rapid City.
Mrs. Alderson and her find
The specimen was found by Mrs. Alderson’s husband in 1961 when he was digging a post for a telephone pole. He brought it home and Mary has kept it ever since. The fossil itself dates back to the Campanian about 70-78 million years ago, when this part of North America was covered by the Western Interior Seaway.
Another interesting find brought in were these:
A geode?
Looks like a galena coconut
The man who brought these in bought them in Morocco. It turns out they’re fake. The mineral inside is obviously galena, the cubic crystal shape and shiny metallic luster are a dead giveaway. But the crystals aren’t intergrown, and those spires in the middle aren’t like anything else seen in galena. The whole thing looks as if it were coated in glue and had galena sprinkled inside like glitter.
To top it all off, the bottom “geode” (the coconut-looking one) appears to be made of a ceramic material. All in all they’re interesting, but definitely man-made.
The Galena Coconut (aka geode) is awesome!