Photo by Yaiba Sakaguchi from http://www.mindat.org/photo-523282.html
These spiny agardite crystals have conichalcite balls on the ends which make them look so otherworldly, but they are from Nevada! Both contain copper arsenate, which gives them their green and turquoise colors.
Photo by Germano Fretti, http://www.mindat.org/photo-448694.html
Rruffite is a crystal named after the Rruff Project which is building a database of Raman spectra, X-ray diffraction data, and photos of very small minerals. This specimen is from the Jote Mine in Chile and belongs to Luigi Chiappino.
As viewed at the November 2014 meeting.
This is a gold sheen obsidian from the personal collection of our members M. Mueller and C. Maazouz. Obsidian is an igneous rock, which means it is formed from lava as it cools and solidifies. Obsidian is usually black. However, some types of obsidian have gas bubbles that create a gold or silver sheen like this.
Photo by Stephanie Reed
This is what a typical Show-Me Rockhounds meeting looks like.
Smiley face agate photo by Cobalt123 from https://flic.kr/p/dVdpEA
An agate dressed up for Halloween, hanging out at the Tucson Rock and Gem Show 2013. Thanks for following us all the way through Agate Month and learning all about these beautiful minerals!
If you’d like to see a list of even more types of agates, go here: http://stoneplus.cst.cmich.edu/agate.htm
Photo by Jerry Schaber at http://www.agateoftheworld.com/timan2.html
Shadow agates are hard to photograph, because it’s more of an effect. When you move shadow agates back and forth, you can see deep, dark areas that appear to move. They look like they are deep inside the stone.
These aren’t technically types of agate according to Mindat, but sometimes they will be described this way in rock shops or on rockhound websites. And these pictures are so great I couldn’t possibly pass them up. An agate with red, orange, or yellow plumes in just the right arangement can be called a flame agate, because it looks like fire.
Photo by Vítězslav Snášel from http://www.mindat.org/photo-114774.html
Frost agate describes the cracked finish on these beads (again, it’s not a mineralogical term). They can also be called cracked agate. The frost effect is heightened when they are blue. Whatever they are, I would totally wear earrings made with these beads.
Photo by Agate Lady from http://agatelady.blogspot.com/2009/06/rain-flower-agates.html
Chinese rain flower agates are found in Nanijing, China in the bed of the Yangtze River. They can also be called Yuhashi or Yuhua stones. The river polishes them smooth, and people often display them in a small bowl of water to bring out the colors. They look very similar to Lake Superior agates, and like Lake Superior agates, they are named after where they came from.
Photo by Verity Woolf, from collection of Jo Woolf. Retrieved from: http://the-hazel-tree.com/2014/01/06/enhydro-agate-a-secret-water-chamber/
Sometimes, agates will have a little bubble of water trapped inside. This is called an enhydro. The water inside is millions of years old! The water can be seen if you shine a light on the agate from behind, or heard if you shake it. Eventually, the water will work its way out and evaporate via small capillaries, but the hollow part will still remain. It is also possible that water could enter the agate through the same capillaries. Enhydros can be found in watery places where agates are found, such as Brazil, Indonesia, and Oregon. Photos don’t show this very well, but on the link in the photo, the owner has some videos that show off the water inside.
For more information about enhydros, go here: http://www.rocksinmyheadtoo.com/Enhydros.htm
From the collection of Dennis Tryon. http://www.mindat.org/photo-374385.html
Brecciated agate is a naturally amalgamated matrix of broken agate fragments. In other words, it’s broken agates stuck together to make one big agate. Sometimes it’s called mosaic agate or ruin agate.
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