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Post by stephan on Dec 27, 2018 23:33:57 GMT -5
Wow! If that was mine, I'd leave it. That is amazing.
Petrified wood? Jasp-agate? It's Howardite from the old-time deposit. It used to be called Plaid Agate and another name is Rattlesnake Agate. I've never run across a definitive explanation of how it was deposited. My own theory is that it was created in a hydrothermal environment and the pattern is due to pulsating waters carrying various metal salts that colored it. I could definitely be wrong. Yup. Saw the trade name, but that didn't tell me much. I tried to figure out what it might be from a minerological stand point (as far as trade names go, I like rattlesnake agate even better). Now, in your pic, it looks wood-like. The link that alikat posted has a Howardite cab that looks kind of like brecciated Jasper. I haven't seen a pic yet that looks like opal. What's the hardness of this stuff? Just to make matters even more fun, it looks like there is meteorite material by the same name.
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Post by vegasjames on Dec 27, 2018 23:51:06 GMT -5
It's Howardite from the old-time deposit. It used to be called Plaid Agate and another name is Rattlesnake Agate. I've never run across a definitive explanation of how it was deposited. My own theory is that it was created in a hydrothermal environment and the pattern is due to pulsating waters carrying various metal salts that colored it. I could definitely be wrong. Yup. Saw the trade name, but that didn't tell me much. I tried to figure out what it might be from a minerological stand point (as far as trade names go, I like rattlesnake agate even better). Now, in your pic, it looks wood-like. The link that alikat posted has a Howardite cab that looks kind of like brecciated Jasper. I haven't seen a pic yet that looks like opal. What's the hardness of this stuff? Just to make matters even more fun, it looks like there is meteorite material by the same name. Jaspers and agates are chalcedonies and opals can lose all their water to form chalcedonies. So maybe it was opal at one time. And yes, there are meteorites called howardites. I have several in my collection. These are sometimes referred to as "rubble piles" as they are formed by an impact in to a planetary body by a meteor that leads to heavy fragmentation. mixing and welding together of the different bodies all in milliseconds. Howardite meteorites can run from around $10-100 per gram and are less dense than most meteorites making them a little harder to identify in the field.
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Post by stephan on Dec 28, 2018 0:01:07 GMT -5
Yup. Saw the trade name, but that didn't tell me much. I tried to figure out what it might be from a minerological stand point (as far as trade names go, I like rattlesnake agate even better). Now, in your pic, it looks wood-like. The link that alikat posted has a Howardite cab that looks kind of like brecciated Jasper. I haven't seen a pic yet that looks like opal. What's the hardness of this stuff? Just to make matters even more fun, it looks like there is meteorite material by the same name. Jaspers and agates are chalcedonies and opals can lose all their water to form chalcedonies. So maybe it was opal at one time. And yes, there are meteorites called howardites. I have several in my collection. These are sometimes referred to as "rubble piles" as they are formed by an impact in to a planetary body by a meteor that leads to heavy fragmentation. mixing and welding together of the different bodies all in milliseconds. Howardite meteorites can run from around $10-100 per gram and are less dense than most meteorites making them a little harder to identify in the field.
I had not thought about dehydrated opal -- which would lead to crazing -- and later healed with agate. Makes sense.
And a brecciated meteorite, so to speak. How appropriate.
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Post by vegasjames on Dec 28, 2018 0:26:08 GMT -5
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gemfeller
Cave Dweller
Member since June 2011
Posts: 3,728
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Post by gemfeller on Dec 28, 2018 0:35:54 GMT -5
stephan , yes I was aware that the name Howardite was a misnomer and that there are meteorites of the same name. This is what Mindat says about its origin: "This material was said to be an opalized/agatized/jasperized tuff infused with chalcedony, in which the plaided or wood grain "appearance" was stated (1940's ?) to be created from the pulsation of iron bearing waters infiltrated through the tuff. Sinkankas (GNA, Vol.1, 1959) depicts similar material which he stated more closely resembled Chert."
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Post by vegasjames on Dec 28, 2018 0:44:28 GMT -5
Jaspers and agates are chalcedonies and opals can lose all their water to form chalcedonies. So maybe it was opal at one time. And yes, there are meteorites called howardites. I have several in my collection. These are sometimes referred to as "rubble piles" as they are formed by an impact in to a planetary body by a meteor that leads to heavy fragmentation. mixing and welding together of the different bodies all in milliseconds. Howardite meteorites can run from around $10-100 per gram and are less dense than most meteorites making them a little harder to identify in the field.
I had not thought about dehydrated opal -- which would lead to crazing -- and later healed with agate. Makes sense.
And a brecciated meteorite, so to speak. How appropriate.
Not all opal crazes as it dries. In fact not all opal is just silicon dioxide. Opal can also contain varying amounts of aluminum oxide, and the higher the aluminum oxide content the harder and more stable the opal is.
There are actually around 300 different types of opal.
A lot of opal is formed from clay, which provides the aluminum oxide. From the clay a silica gel is first formed. As the atoms in the silica gel start to move closer together they squeeze out water, eventually leading to opal formation. If all the water gets squeezed out you have chalcedony.
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Post by Rockoonz on Dec 28, 2018 2:53:22 GMT -5
Last Howardite post from me, since we pretty much hijacked the thread here for a while.
The newer stuff with the smaller, tighter pattern had been called Royal Flamingo for the past few years. I'm glad Jeffrey found this stuff, 'cuz we know him too and he's a good guy.
I'd always heard Howardite is common opal in volcanic ash tuff. Never seen any definitive documentation on that... . I got some of the Royal Flamingo from christopherl1234 at quartzsite a couple years ago, my understanding is it's from a completely different site, what I got doesn't look like the stuff from Jefferys claim. vegasjames it is a claim. Jeff doesn't do public digs on his claims AFAIK.
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Post by vegasjames on Dec 28, 2018 3:33:53 GMT -5
Last Howardite post from me, since we pretty much hijacked the thread here for a while.
The newer stuff with the smaller, tighter pattern had been called Royal Flamingo for the past few years. I'm glad Jeffrey found this stuff, 'cuz we know him too and he's a good guy.
I'd always heard Howardite is common opal in volcanic ash tuff. Never seen any definitive documentation on that... . I got some of the Royal Flamingo from christopherl1234 at quartzsite a couple years ago, my understanding is it's from a completely different site, what I got doesn't look like the stuff from Jefferys claim. vegasjames it is a claim. Jeff doesn't do public digs on his claims AFAIK. According to Mindat the claims are very recent as in January 2018. I was looking in to this long before this date.
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Post by Rockoonz on Dec 28, 2018 4:17:46 GMT -5
I got some of the Royal Flamingo from christopherl1234 at quartzsite a couple years ago, my understanding is it's from a completely different site, what I got doesn't look like the stuff from Jefferys claim. vegasjames it is a claim. Jeff doesn't do public digs on his claims AFAIK. According to Mindat the claims are very recent as in January 2018. I was looking in to this long before this date. Sounds about right. It takes several months for a claim to be publicly filed after the papers are turned in, even though it takes effect when it's posted. The smart thing to do is dig hard during that time, once mindat puts it on their map it becomes fair game for hundreds of claim jumpers.
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Post by vegasjames on Dec 28, 2018 20:59:01 GMT -5
According to Mindat the claims are very recent as in January 2018. I was looking in to this long before this date. Sounds about right. It takes several months for a claim to be publicly filed after the papers are turned in, even though it takes effect when it's posted. The smart thing to do is dig hard during that time, once mindat puts it on their map it becomes fair game for hundreds of claim jumpers. The place I was going go look was not even close to there. Where I was going to look was around an old mine that was called the Howardite Claim.
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sophia13
spending too much on rocks
RIP Jason Strickland, AKA sophia13
Member since March 2018
Posts: 327
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Post by sophia13 on Dec 30, 2018 21:23:05 GMT -5
So, I see Howardite is popular.
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Post by Rockoonz on Dec 31, 2018 3:16:45 GMT -5
So, I see Howardite is popular. Yes it is, sorry for the hijacking.
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NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,630
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Post by NRG on Dec 31, 2018 13:51:01 GMT -5
So, I see Howardite is popular. It is amazing stuff. And expensive. I meant to add it to the list. Not hijack your thread. Humble apologies.
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sophia13
spending too much on rocks
RIP Jason Strickland, AKA sophia13
Member since March 2018
Posts: 327
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Post by sophia13 on Dec 31, 2018 21:19:25 GMT -5
No worries, I enjoy all the posts. I learn from near about every one.
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