Recognize this Lithic??

[CMD]

Paul, thanks, don't knock yourself out, but hope you find the photos you're thinking of.
Arrow, thanks, I think you mean "matrix", not "cortex".
Hoss, thanks, in comparing both under a loupe, the little inclusions you spotted in the bigger piece are whitish, and I think the reason Paul was thinking of a porphyritic felsite. They might be in the same family material wise, not certain, can't ID the material of the smaller one, either. I'll send photos to Moody as well, thanks, hadn't thought of that. Porphyritic felsite seems like a decent candidate, though. I think this one is a porphyry material....



At any rate, it never looked like anything that would lead me to say "can't be RI", and if Paul's right, even less reason to doubt it now. It is nice material too...

[pkfrey]

The form and material both look northeasterly to me. I wouldn't have a problem if someone said it was from RI. There is a specific stone called felsitic porphyry, probably hard to work, but does flake with a conchoidal fracture.

[gregszybala]

Does kind of look like Flint Ridge, Moss Agate variety but your piece doesn't look waxy, slick enough.
Breathitt could be a likely candidate as well based on color, texture and translucency. But very, very rarely used to make points.
But I really don't think this lithic has come from the Midwest.

[Pele]

I wouldn't rule Rhode Island out quite yet. It's possible it was from there. While it's hard to conclusively identify rocks from a photo, there are many aspects of this point that remind me of things I've seen in the volcanic rocks around NC. Here is my quick answer, but those interested in my thought process (and a mini geology lesson) can read the next two paragraphs. I think the dark parts are a plagioclase-bearing, silica-rich lava rock that had fractures running through it. The matrix is probably chalcedony deposited in those cracks by hydrothermal fluids. The light-colored pieces in the matrix are probably bits of rock that were broken off and altered by the hydrothermal fluids. If you can take the rock into the RI Geologic Survey's office, they can give you a more certain opinion.
Thought process:
While I'm not overly familiar with the specifics of Rhode Island's geology, it is old Avalonian material, which is an old microcontinent believed to have started as a volcanic island arc off the coast of Gondwana (ancient Africa and South America). North Carolina's Piedmont also formed as peri-Gondwanan island arcs, so I would expect some general similarities in rock type and geologic processes.
First of all, it looks like the dark parts sort of fit back together like a puzzle. There are a couple of ways we can achieve this: 1. as lava flows the surface cools faster than the underside and breaks apart into what we call a hyaloclastic texture; or 2. the rock had a preexisting fracture in it. I do think this is a silica-rich lava like dacite, rhyo-dacite (think Morrow Mountain for those familiar with NC), or maybe rhyolite, and the white specs are most likely mineral grains (plagioclase). If this were a hyaloclastic texture, the matrix would be made of the same stuff as the clasts, so I wouldn't expect it to be translucent. (It could alter to a different color, but should still be opaque). This makes me lean more toward option two. Volcanic systems have a lot of hydrothermal fluids, which are basically hot, silica-rich groundwater. These fluids deposit material like chalcedony in whatever nearby cracks they can find. The process can break off and alter fragments of rock to the whitish-looking pieces in the matrix. (Felsic rocks usually form light colored weathering rinds.) Hope this helps!

[CMD]

Thank you for the detailed analysis, Pele. Much appreciated. I never dismissed a RI origin, but the circumstances of purchase did leave doubts. Just a box of points in an antique shop. Store owner said from West Greenwich, RI. I bought a large quartzite blade that was certainly right for this region, and this point. The rest of the box was clearly not from this region, and theirin lay the problem. I felt the lithic could easily come from here, but I was just not familiar with it, but I took the chance it was. Between your suggestions and Paul's(pkfrey), I'm sure it is from this region now, and I'm glad I asked!

[CMD]

Hoss wrote:

Years ago I had a point I got from Cordeiro It looked a lot like that material to me.  I think Moody owns it now.  I do not even have a picture of it. It was a crude lanceolate shaped point quite possibly a late paleo form.
Is the base on your point Heavily ground? Doves are noted to have heavily ground stem bases.

  No, don't think it has any grinding, Hoss.  Not serrated, but kind of erose edges. Maybe it's a Kirk? :dunno:

[Kyflintguy]

Hey Charlie I bumped this back up because I wanted you to take a look at the piece of material that Jay sent Ron to Knapp. I think this point in question is likely the same stuff but your artifact was made from a piece close to the outer cortex of the material. I know you said you bought it and perhaps it was an import but looks to me like it may be local?

Still don't know what to call it and call me crazy for associating the two but my gut tells me they are one in the same just different portions of the nodule.
https://forums.arrowheads.com/forum/...-island-lithic

[Ron Kelley]

Agreed

[CMD]

Hey Charlie I bumped this back up because I wanted you to take a look at the piece of material that Jay sent Ron to Knapp. I think this point in question is likely the same stuff but your artifact was made from a piece close to the outer cortex of the material. I know you said you bought it and perhaps it was an import but looks to me like it may be local?

Still don't know what to call it and call me crazy for associating the two but my gut tells me they are one in the same just different portions of the nodule.
https://forums.arrowheads.com/forum/...-island-lithic

Only just now saw this comment in my old thread, Josh. And oddly enough, I had that point in hand today. I'll check it out better mañana, and get back to you, but, off the top, yes, the translucent areas are remindful of Jay's material.

[CMD]

OK, well we might as well put up a link to Jay's thread about his mom's point, which has a lot of photos of the raw material he collects at his stream bed location in Rhode Island. This thread also included a raw chunk of something, either chalcedony or agate, that I found in a stream bed a few miles east of Jay's site, as well as artifacts I've found that might be related:

https://forums.arrowheads.com/forum/...s-little-point

So the question is whether the dovetail in this thread is Jay's material. Jay is best equipped to answer that, not myself, because he finds the raw material. Paul Frey identified the dovetail as possibly a porphyritic felsite. Felsite is a field term, meaning only chemical testing can determine if it is either andesite or rhyolite. Our old friend painshill taught us that. I will throw up a few more photos of this dovetail. And offer this opinion: I suspect the veins of orangey material are chalcedony. And the black areas are the host rock in which the chalcedony is present as veins. We find jasper here that contains veins of chalcedony, and I'll show a point of that as well.

So, I do not know what the host rock is, but Paul had suggested felsite. Works for me. At the least, I have no problem visualizing this being a local/regional find. Only Jay can best answer if, in its totality, including the host rock, it seems like the same stuff he and Doc find. I do believe the chalcedony is present as veins in a host rock. It may be that Jay is finding larger chunks of chalcedony alone, without a host rock? Might have originally been present in a host rock, but he's finding just the chalcedony. Dunno. Need to be a geologist, and one versed in RI geology. Or I need to be painshill, but, alas, none of us are, lol.

First two photos are both sides of this dovetail. I assume it's a dovetail, but that's not important.

[CMD]

OK, per usual, the number of photos I can post in one comment is up to the whims of something out of my control, lol. So, here are the ones I could not post above....

The last photo is a jasper point with chalcedony veins. Yellow and brown jasper are found in both RI and Pa, and cannot be distinguished by eyeball alone. This point is from RI...

[CMD]

For further reference, here are examples of chalcedony jasper from Diamond Hill, Cumberland, RI. This is a different locale from Limerock, where both my wife and I, as well as prehistoric peoples, sourced jasper.

https://www.mindat.org/photo-383955.html

https://www.mindat.org/photo-300310.html

[CMD]

Hey Charlie I bumped this back up because I wanted you to take a look at the piece of material that Jay sent Ron to Knapp. I think this point in question is likely the same stuff but your artifact was made from a piece close to the outer cortex of the material. I know you said you bought it and perhaps it was an import but looks to me like it may be local?

Still don't know what to call it and call me crazy for associating the two but my gut tells me they are one in the same just different portions of the nodule.
https://forums.arrowheads.com/forum/...-island-lithic

So, I think the best answer I can offer, with the aim of addressing your observation Josh, is that Jay is best equipped to tell us if he finds any of his chalcedony chunks that include a host rock that resembles closely the black host rock seen in this point.

Edit: Josh, if you go back to Ron's thread, it looks like the piece Jay sent him includes limestone as a host rock for the chalcedony. Ron pointed that out to me this morning.....

[Rybo]

Ir looks like a type of Agatized Coral to me. We have that down here. It comes in many colors, and is very translucent. If i remember correctly there are 8 different kinds, although even they can appear different from each other, and that is because of how it is made.

When the coral begins to fossilize, minerals start leaking into the differnt shape corals, and over thousands to millions of years replaces a layer of the coral which begins to fossilize and harden the monerals in the layer they formed. Then more time passes and different minerals seep down into the coral and continue the process. Then throw it in the oven, ( allow it to fossilize for millions of years), and bam! You get a master piece!! The Agatized Coral closest to my region, is approx 38 to 40 million year-old! Its like finding a gem. Its also our state stone, although i dont think anyone here knows that, lol. Unfortunately the piece i have that resembles yours, is not here with me so i cant send pic. Ill look and see if i have any around here that ressemble it. If you research it online you will see crazy looking pieces that are cut and polished, which obviously look different than what it looks like when made into authentic artifact.

[Rybo]

Hi CMD, its Rybo from down here in the South East region. From what ive seen it looks like it could be Agatized Coral.
Agatized coral is formed by the combination of fossilization, mineral inclusions, and the right conditions for millions of years. After the coral dies off, the hard limestone shell formed by the gases the coral polyps gave off by removing the oxygen from the salt water, mixed with lime from the ocean floor, acts as a "cast" for nature's master piece.
As the fossilized coral lies deep underground, acidic groundwater slowly seeps into and through the pourous skeleton, it washes the calcium carbonate from the coral and replaces it with silica along with other trace mineral deposits such as manganese or iron. The gasses formed from the decomp of the materials combined with the including minerals cause layers of coral to fossilize with awe - taking results. Climate change, natural events, Etc result in different minerals being introduced throughout the fossilization process, giving us the Agate look or colored layers and color variety.

This process occurs over a long period of approximately 20 million to 38 million years!That may be the average in my area, but there have been species of the coral discovered to be 500 million years old although found in some spots globally, the primary source for agatized Coral is good old Florida.




I've post some examples from online to check out. CMD, I'm not having much luck finding my specimens close to your color, but i will keep at it. After looking at your pics again, id put money on it. Thats def Ag Coral. Wish i could tell you where its from, but i can say it looks a lot like some ive found in my regeion. Actually if i can find

[Rybo]

Hi CMD, its Rybo from down here in the South East region. From what ive seen it looks like it could be Agatized Coral.
Agatized coral is formed by the combination of fossilization, mineral inclusions, and the right conditions for millions of years. After the coral dies off, the hard limestone shell formed by the gases the coral polyps gave off by removing the oxygen from the salt water, mixed with lime from the ocean floor, acts as a "cast" for nature's master piece.
As the fossilized coral lies deep underground, acidic groundwater slowly seeps into and through the pourous skeleton, it washes the calcium carbonate from the coral and replaces it with silica along with other trace mineral deposits such as manganese or iron. The gasses formed from the decomp of the materials combined with the including minerals cause layers of coral to fossilize with awe - taking results. Climate change, natural events, Etc result in different minerals being introduced throughout the fossilization process, giving us the Agate look or colored layers and color variety.

This process occurs over a long period of approximately 20 million to 38 million years!That may be the average in my area, but there have been species of the coral discovered to be 500 million years old although found in some spots globally, the primary source for agatized Coral is good old Florida.

Couple pics from online to show variety of color. First one is similar to your type. I am still trying to find the piece im thinking of, that should be same.