Rhyolite, Obsidian & the Friday Finds
Ah, the joys of discovering a new rock. I had a custom order necklace and earrings to make this week, and since the supplier who gives me volume discount does not carry 5mm Swarovski rounds in AB, I had to go to the more expensive retailer I used to frequent. This was actually good, because they carry stones and cuts the other guy doesn't, and I picked up the African turquoise jasper I wrote about the other night, as well as some really nice rhyolite. I didn't know what rhyolite was (I don't know much about rhyolite, but I know what I like...), so that necessitated a very looooong search on the web. Which turned up a lot about the ghost town called Rhyolite in the Nevada desert, but ghost towns were not what I was after. I found a lot of pretty vague sites about rhyolite, but none of the definitive sites I know I can trust had anything about it. I was, however, able to cobble together the following:
Rhyolite is an igneous rock extremely similar to granite. It's formed when magma is expelled pretty violently from a volcano and then cools quickly in open air. Because of it's high silicon content, rhyolite is a very smooth stone with a glasslike sheen and very tiny crystalline structure, composed of feldspar, quartz, mica, and whatever other minerals may have been present at the time of the eruption. (If the eruption which produces rhyolite is violent enough and a lot of air mixes in with the magma, you end up with pumice.) Rhyolite has a hardness of 6 and is found in shades of white, grey, green, pink/red, purple, yellow and brown. It may be banded or contain swirling layers of different color and texture, or crystals of quartz, feldspar, mica or hornblende. Green rhyolite is often referred to somewhat erroneously as rainforest "jasper". (it is not a jasper)
The search for information on rhyolite (and believe me, digging up the Mohs on it took some serious surfing), led to the 411 on another igneous "rock," obsidian. Like rhyolite, obsidian has a very high silicon content. Containing at least 70% silicon, obsidian is actually a natural glass, and it too is produced by rapidly cooling lava - even more rapidly cooling than rhyolite - and generally lava which has hit sea water. Obsidian lacks crystalline structure and is not considered a true mineral, but it has a Mohs hardness of 5 - 5.5 and is often used for ornamental purposes, as well as in cardiac surgery; blades crafted from obsidian have a much sharper edge than those of surgical steel and result in less trauma to the heart tissue. While most people think black when they think of obsidian, obsidian often appears grey when cut at a specific angle and is also found in smokey grey/brown or dark green. Small bubbles of air trapped inside the glass can also lend a sheen of gold, green, purple, "rainbow", silver or red. Some obsidian also contains white inclusions resembling snowflakes. Perhaps the most treasured form of obsidian is that of naturally rounded pebbles called "Apache Tears." These nuggets have "windows" through which one can look and see what appears to be a tiny tear suspended inside. Native American legend has it each tiny inclusion was shed by an Apache woman to mourn warriors driven over an Arizone cliff by the US cavalry during the late 1800's. Where each tear struck the ground, it was turned to stone, and natural Apache Tear nuggets are given now as a token of good luck.
And now, the Friday Finds. :)
The Fens is a painting done by a blogging buddy of mine named Amy. Her art "blog" is located here. I also like the painting entitled "Archetypal Provence". It totally reminds me of standing in a field of sunflowers driving back to Paris from Axe-les-Thermes summer of 2003. Man, I miss France.
If you go to this page, you can see a picture of the Roman thermal bath at Ax. In fact, if you look at this picture of the bath, you can see where I sat and put my feet in after hiking about 2km nearly straight up the side of a mountain and another 3 or so more up a road to the finishing stage of one of the legs of the Tour de France (and then all the way back down again!). I was sitting about 4 - 5 feet away from the upper right corner of the bath. Which is not quite in the middle of the righthand side, there. Man, that picture really takes me back. That was a great night. All these people had come into town or were staying at hotels there for the Tour, and a bunch of us were seated around the bath, with our feet in the water. It was a nice cool night, so the water felt *great*. Everyone was talking pretty quietly but happily, and there was some laughing. We just sat and listened to people talk and talked a little ourselves and watched the kids play. After that, me and Marie-Pierre walked through Ax, which is a small little medieval town, and then went back to the car and drove back to her parents' chateau just a little bit outside town. The chateau is really more of a chalet, I guess, in the traditional sense of the word, all A-frame and wood, with narrow stairs going to the upper floor and great wooden doors...just an awesome place. I loved it.
Here's the official website of Ax les Thermes, in translated english. The Photos page has some great pictures.
Here's the site in it's normal French, for those of you who speak French.
I can't remember if I posted this or not, but here's the link to my brother Tom Womack's WWII history book about the Dutch Naval Air Force's contribution to the war against Japan. He taught himself Dutch when he was like 19 so that he could converse with other Dutch writers and historians. He's a pretty smart guy. :)
And this is a link to my friend Jodie's book. Jodie is quite the accomplished and very cool human being. I miss her a lot since she had to go and move to Atlanta. You can read a little about Jodie and why she wrote the book here.
And last, if you ever need to figure out how to repair a Native American flute (don't laugh; it could happen), this page might prove helpful.
Sorry no fashion finds this week. I haven't had time to scout any out.
bis spater, gator!
Jenie
Rhyolite is an igneous rock extremely similar to granite. It's formed when magma is expelled pretty violently from a volcano and then cools quickly in open air. Because of it's high silicon content, rhyolite is a very smooth stone with a glasslike sheen and very tiny crystalline structure, composed of feldspar, quartz, mica, and whatever other minerals may have been present at the time of the eruption. (If the eruption which produces rhyolite is violent enough and a lot of air mixes in with the magma, you end up with pumice.) Rhyolite has a hardness of 6 and is found in shades of white, grey, green, pink/red, purple, yellow and brown. It may be banded or contain swirling layers of different color and texture, or crystals of quartz, feldspar, mica or hornblende. Green rhyolite is often referred to somewhat erroneously as rainforest "jasper". (it is not a jasper)
The search for information on rhyolite (and believe me, digging up the Mohs on it took some serious surfing), led to the 411 on another igneous "rock," obsidian. Like rhyolite, obsidian has a very high silicon content. Containing at least 70% silicon, obsidian is actually a natural glass, and it too is produced by rapidly cooling lava - even more rapidly cooling than rhyolite - and generally lava which has hit sea water. Obsidian lacks crystalline structure and is not considered a true mineral, but it has a Mohs hardness of 5 - 5.5 and is often used for ornamental purposes, as well as in cardiac surgery; blades crafted from obsidian have a much sharper edge than those of surgical steel and result in less trauma to the heart tissue. While most people think black when they think of obsidian, obsidian often appears grey when cut at a specific angle and is also found in smokey grey/brown or dark green. Small bubbles of air trapped inside the glass can also lend a sheen of gold, green, purple, "rainbow", silver or red. Some obsidian also contains white inclusions resembling snowflakes. Perhaps the most treasured form of obsidian is that of naturally rounded pebbles called "Apache Tears." These nuggets have "windows" through which one can look and see what appears to be a tiny tear suspended inside. Native American legend has it each tiny inclusion was shed by an Apache woman to mourn warriors driven over an Arizone cliff by the US cavalry during the late 1800's. Where each tear struck the ground, it was turned to stone, and natural Apache Tear nuggets are given now as a token of good luck.
And now, the Friday Finds. :)
The Fens is a painting done by a blogging buddy of mine named Amy. Her art "blog" is located here. I also like the painting entitled "Archetypal Provence". It totally reminds me of standing in a field of sunflowers driving back to Paris from Axe-les-Thermes summer of 2003. Man, I miss France.
If you go to this page, you can see a picture of the Roman thermal bath at Ax. In fact, if you look at this picture of the bath, you can see where I sat and put my feet in after hiking about 2km nearly straight up the side of a mountain and another 3 or so more up a road to the finishing stage of one of the legs of the Tour de France (and then all the way back down again!). I was sitting about 4 - 5 feet away from the upper right corner of the bath. Which is not quite in the middle of the righthand side, there. Man, that picture really takes me back. That was a great night. All these people had come into town or were staying at hotels there for the Tour, and a bunch of us were seated around the bath, with our feet in the water. It was a nice cool night, so the water felt *great*. Everyone was talking pretty quietly but happily, and there was some laughing. We just sat and listened to people talk and talked a little ourselves and watched the kids play. After that, me and Marie-Pierre walked through Ax, which is a small little medieval town, and then went back to the car and drove back to her parents' chateau just a little bit outside town. The chateau is really more of a chalet, I guess, in the traditional sense of the word, all A-frame and wood, with narrow stairs going to the upper floor and great wooden doors...just an awesome place. I loved it.
Here's the official website of Ax les Thermes, in translated english. The Photos page has some great pictures.
Here's the site in it's normal French, for those of you who speak French.
I can't remember if I posted this or not, but here's the link to my brother Tom Womack's WWII history book about the Dutch Naval Air Force's contribution to the war against Japan. He taught himself Dutch when he was like 19 so that he could converse with other Dutch writers and historians. He's a pretty smart guy. :)
And this is a link to my friend Jodie's book. Jodie is quite the accomplished and very cool human being. I miss her a lot since she had to go and move to Atlanta. You can read a little about Jodie and why she wrote the book here.
And last, if you ever need to figure out how to repair a Native American flute (don't laugh; it could happen), this page might prove helpful.
Sorry no fashion finds this week. I haven't had time to scout any out.
bis spater, gator!
Jenie
posted by Jenie at 2:35 AM
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