I’ve always loved gems and minerals, I had a rock collection as a kid and my parents were always very supportive of my eccentricities involved in the obsession. I recently discovered that you can buy unopened geodes off eBay, the 10 year old in me jumped at the chance.
Here is a gallery of the process.
Once it was open I was curious about what I had, it was certainly beautiful, but I like learning. I found www.americangeode.com and emailed them. Charles, was kind enough to email me back.
From the outside, which shows its origin in an air pocket in an underground volcanic vein, to that quartz and chalcedony interior, that is a geode from the Chihuahua region of Mexico. That’s quartz inside and chalcedony, which is the micro-crystal smoother interior.
From various Wikipedia pages I discovered that Chalcedony is a cryptocrystalline form of silica, composed of very fine intergrowths of the minerals quartz and moganite. Moganite is silicon dioxide, a silicate mineral. It is considered a polymorph of quartz which means that it has the same chemical composition as quartz, but a different crystal structure.
The Chihuahua region, yes like the dog, straddles the U.S.-Mexico border on the Mexican Plateau. On the United States side, it occupies much of southwestern Texas and small parts of New Mexico and Arizona. On the Mexican side, it covers the northern half of the state of Chihuahua, along with the majority of Coahuila, north-eastern Durango, the extreme northern part of Zacatecas, and small western portions of Nuevo León.
Now I have to figure out how not to fill my home with these…