Blue Montana compared to blue coral

[Mark K]

I actually found and still have a blue MT agate. I made sure it does not get lost.

[jamesp]

Thanks for making me feel like a dumb a$$ and thanks for the welcome! I think that's cool that you can play with pictures like that, I'll be lucky if I can figure out how to post pictures.

Read more: forum.rocktumblinghobby.com/thread/64332/blue-montana-compared-coral?page=2&scrollTo=727481#ixzz2tUnJH0ID

We all get tricked by photoshoppers at one time or another. Makes it a new experience in what may be perceived.LOL.

[jamesp]

James, Though there are many opinions on Chalcedony vs agate I would say that the healed fractures are definitely Chalcedony. If my thought is correct, agate is a variety of translucent Chalcedony that is concentrically banded. The darker blue little agate above has visible banding, and is an agate.


Read more: forum.rocktumblinghobby.com/thread/64332/blue-montana-compared-coral?page=2&scrollTo=727534#ixzz2tUoJ55dR

A lot of interpretation on that subject Bill. I am trying to figure out what is precipitating through the limestone to make the coral. The Montana agate has water lines. Guessing that that banding
is water levels. Is chalcedony always related to water, like transported by water? I just thought about the springs of the large Ocala Aquifer. The coral is found in territory that is peppered with those
free flowing springs if the altitude is at the 'coral altitude'. About every one of my coral rivers has spring boils. And a lot of protest about not developing the springs to bottle water out of them.
Sometimes there are hot spots and cold spots where the water is percolating up through the sand bottom. Sometimes blasting out of a limestone wall. Regardless, lots of water. And it has a
long list of minerals and metals in it. It is very clean too.

[grayfingers]

James, as to the MT agates being formed in layers/waterline. I find it odd how some are flat "waterline" while some are Concentric bands, and others are botryoidal, (turtleback). Some are a combination of two of the above. I believe it is generally accepted that the ground water precipitates down through silica rich sand, soil or ash and is deposited over the last such precipitation. Wonder how long it may have been between layers? I think the ones that have both waterline and concentric bands may have been tilted during the formation, like in an earthquake?

How the corals were silicified. . . There really is no sign I have seen of layering in your corals, maybe they sat in a silica rich soup, and soaked it in like a sponge? (As opposed to being laid down in layers/bands)

[jamesp]

I know the Montanas can be combo. They are special that way. Could be the violence down below tilting them-interesting. Also parallel bands in 2 directions.
The violence down below is common in the rockies. No surprise that the agates were tilted.

I like the soup/sponge theory. No bands in coral. Just fades of color. Some obnoxious, some beautiful. Many are not silicified on the inside. Like unfinished and pulpy.
But looks like it entered like a sponge, from all directions. The unfinished ones often have the best color, but a pulpy center;and a 1-2 inch thick silicified shell.

Weird. All of it.

[drocknut]

I have some blue from near Avon, Montana. It isn't as blue as what you have but still cool. I believe what you have is called Madison Blue. There is also White Earth Agate which is sometimes fire agate.

[jollyrockhound]

Blue agate is cool I have some near me which is very blue tho its in basalt and hard to extract.

[jamesp]

Feb 16, 2014 11:10:07 GMT -5 drocknut said:

I have some blue from near Avon, Montana. It isn't as blue as what you have but still cool. I believe what you have is called Madison Blue. There is also White Earth Agate which is sometimes fire agate.

That ghost blue is common in a lot of agates and fills.
I f you look up chalcedony on google you see mostly blues similar in color to the Montana blue and that particular coral.
A lot of 5-15 pound corals i find has a lighter hue of that ghost blue color. Not very flashy but the blue tint is there.
The Florida geologists say that it is a chalcedony fill.
some examples from google for what it is worth :

[jamesp]

Feb 16, 2014 21:48:47 GMT -5 jollyrockhound said:

Blue agate is cool I have some near me which is very blue tho its in basalt and hard to extract.

Basalt is some tough stuff.

[jcinpc]

James, I find some blue at certain sites, it is really the dendrites making this color, I have found a few pieces where the actual polyps are blue, these are very rare to find
I do find heads that are blueish in one of our local Fl rivers, this head below is one and so is the little man cab I made and wore

[jamesp]

James, I find some blue at certain sites, it is really the dendrites making this color, I have found a few pieces where the actual polyps are blue, these are very rare to find
I do find heads that are blueish in one of our local Fl rivers, this head below is one and so is the little man cab I made and wore


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Great stuff jc. Looks like blue and a few other colors thrown in. You mentioned the clay. That light blue clay gives me blue corals.
If you have a big enough pry bar to get it out of the clay.LOL.

[tandl]

way cool blue coral . i have this quartz replaced sponge i found ,looks like a blue and black montana agate, i will have to get it on here.