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Post by holajonathan on Oct 24, 2021 14:41:39 GMT -5
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Post by holajonathan on Oct 24, 2021 15:20:24 GMT -5
I cut a 4mm slab to see if the color requires depth (as some rocks do). Nope. Still purple.  |
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AzRockGeek
has rocks in the head
Member since September 2016
Posts: 703
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Post by AzRockGeek on Oct 24, 2021 15:29:16 GMT -5
Never seen a purple Montana. Cool surprise.
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Post by drocknut on Oct 24, 2021 15:29:27 GMT -5
That's amazing. I've never seen a Montana Agate with purple in it but I suppose anything is possible. Very cool.
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Post by holajonathan on Oct 24, 2021 16:32:34 GMT -5
That's amazing. I've never seen a Montana Agate with purple in it but I suppose anything is possible. Very cool. Me neither. If it came from Tony's Montana agate pile I assume that is where it came from. Everything about it looks like a Montana agate except the color. And I don't know of any other nodular agates that look like purple Montana agates. |
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Post by catmandewe on Oct 24, 2021 17:26:42 GMT -5
Thats cool!!
You might ought to send it back so I can inspect it further!
Tony
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Post by rockjunquie on Oct 24, 2021 18:50:12 GMT -5
WOW!
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Post by jasoninsd on Oct 24, 2021 20:31:02 GMT -5
That might be purple...but everyone looking at these pictures are GREEN with envy! LOL Nice cuts Jonathan!  |
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Post by holajonathan on Oct 25, 2021 0:09:27 GMT -5
That might be purple...but everyone looking at these pictures are GREEN with envy! LOL Nice cuts Jonathan! If you saw how many horribly fractured or solid brown colored or otherwise uninteresting ones I have cut recently, I think you would agree that I deserved a purple one as a consolation prize. I read somewhere that only about 15% of Montana agates produce cab worthy cuts, and my experience confirms that. I cut at least 10 to find 1 that might make really nice cabs. And even then, a lot fracture when cutting performs. |
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Post by stephan on Oct 25, 2021 1:22:01 GMT -5
I’ve had one that was purple — nothing like yours — just a hint. And, if you look closely a hint of wood grain. That’s when I found out about them being limb casts.That was more than 10 years ago. Haven’t seen another until now. I know… it didn’t a happen without at least one pic:  Montana Moss Agate Shield (Backlit) by sdttds, on Flickr |
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Post by stephan on Oct 25, 2021 1:25:27 GMT -5
That's amazing. I've never seen a Montana Agate with purple in it but I suppose anything is possible. Very cool. Very possible. Purple comes from iron, as do the brown/black inclusions that make the “moss” in Montanas. |
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Post by stephan on Oct 25, 2021 1:29:58 GMT -5
Picture 7 is Homer Simpson in profile (though he seems to be wearing a hat or a Marge wig). It also seems to have touch of purple.
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Post by MsAli on Oct 25, 2021 7:51:15 GMT -5
That doesn't quite look right for Montana but you never know. I'd say based off the second one some strays got in the box.
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Post by holajonathan on Oct 25, 2021 8:12:32 GMT -5
I’ve had one that was purple — nothing like yours — just a hint. And, if you look closely a hint of wood grain. That’s when I found out about them being limb casts.That was more than 10 years ago. Haven’t seen another until now. I know… it didn’t a happen without at least one pic: Montana Moss Agate Shield (Backlit) by sdttds, on Flickr Very cool. I can definitely see the hint of purple in the bottom half. It looks somewhat similar to the one I cut in terms of lots of moss in translucent agate. |
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Post by holajonathan on Oct 25, 2021 8:14:36 GMT -5
Picture 7 is Homer Simpson in profile (though he seems to be wearing a hat or a Marge wig). It also seems to have touch of purple. I see it. I wonder if the purple tint in that photo is from my hand underneath. I will investigate. I have yet to find a Montana iris agate -- one of my top lapidary goals. |
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Post by holajonathan on Oct 25, 2021 8:36:24 GMT -5
That doesn't quite look right for Montana but you never know. I'd say based off the second one some strays got in the box. I guess it depend on how you define "Montana agate." My definition would start with the geographic location where they are found (the Yellowstone river and tributaries) and where / how they were formed (the burial of trees into basalt beds by volcanic activity around 80 million years ago). My understanding is that all Montana agates were formed when trees were buried by volcanoes and the wood was later replaced by agate. The classic Montanas are limb casts, where the buried wood served only as a mold, and there are few obvious traces of wood grain or wood pattern in the agate. Lots of these classic looking Motnana agates still look like pet wood on the exterior only, unless they have been river worn. A lot of pet wood (not well agatized) is also found on the Yellowstone and dates to the same volcanic activity that created Montana agates. Finally, there is a lot of pet wood on the Yellowstone that is fully agatized, but still retains a lot of characteristics of pet wood. Many such rocks look like normal Montana agates on the outside (such as the second rock I posted) but have some pet wood characteristics on the inside. I have probably about about 500 pounds of Montana agates from Tony and a few other sources, and I'd say at least 10% fall into this category. I think a good argument could be made that they are "Montana agates," but I understand the argument to the contrary. Even a lot of classic looking Montana agates (like the 5th and 6th rocks that I posted) have some hints of wood grain when held up to the light. So in conclusion: - All Montana agates are limb casts. - Not all Montana pet wood is agate. - Many rocks found on the Yellowstone fall somewhere in between. |
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Post by stephan on Oct 25, 2021 8:37:44 GMT -5
Picture 7 is Homer Simpson in profile (though he seems to be wearing a hat or a Marge wig). It also seems to have touch of purple. I see it. I wonder if the purple tint in that photo is from my hand underneath. I will investigate. I have yet to find a Montana iris agate -- one of my top lapidary goals. Iris agate would be super-cool. The holy grail! Hope it’s not your hand. |
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Post by stephan on Oct 25, 2021 8:39:22 GMT -5
That doesn't quite look right for Montana but you never know. I'd say based off the second one some strays got in the box. I guess it depend on how you define "Montana agate." My definition would start with the geographic location where they are found (the Yellowstone river and tributaries) and where / how they were formed (the burial of trees into basalt beds by volcanic activity around 80 million years ago). My understanding is that all Montana agates were formed when trees were buried by volcanoes and the wood was later replaced by agate. The classic Montanas are limb casts, where the buried wood served only as a mold, and there are few obvious traces of wood grain or wood pattern in the agate. Lots of these classic looking Motnana agates still look like pet wood on the exterior only, unless they have been river worn. A lot of pet wood (not well agatized) is also found on the Yellowstone and dates to the same volcanic activity that created Montana agates. Finally, there is a lot of pet wood on the Yellowstone that is fully agatized, but still retains a lot of characteristics of pet wood. Many such rocks look like normal Montana agates on the outside (such as the second rock I posted) but have some pet wood characteristics on the inside. I have probably about about 500 pounds of Montana agates from Tony and a few other sources, and I'd say at least 10% fall into this category. I think a good argument could be made that they are "Montana agates," but I also understand the argument to the contrary. Even a lot of the classic looking Montana agates (like the 5th and 6th rocks that I posted) have some hints of wood grain when held up to the light. So in conclusion, all Montana agates are limb casts, but not all Montana pet wood is agate. And there are a lot of rocks found on the Yellowstone that fall somewhere in between. This is my understanding, also. |
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Post by holajonathan on Oct 25, 2021 8:44:02 GMT -5
The outside of the purple rock looked just like the white skinned Montana agates in this photo:  I am confident that the purple rock came from the Yellowstone river. If it were clear agate and not purple, it would look like a classic dendritic Montana moss agate. The purple is the only thing that sets it apart. The second rock I posted (looks like a Montana agate on outside, but more like agatized pet wood on the inside, it a tougher call. |
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Post by holajonathan on Oct 25, 2021 9:03:43 GMT -5
 Black pet wood limb cast coming from the Tom Miner Basin, adjacent to the Yellowstone. Described here as a limb cast agate and "not technically petrified wood." Looks very similar to the black rock I posted. |
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