Not the paper I referenced above, but still relevant.
“The most fabulous artifact discovered so far at Morgan did not come from any of our excavations. It is an exquisite human effigy carved from a piece of deer antler. The artifact was found by a local resident of Pecan Island in a load of fill obtained from the leveled Mound 2. Although this rather exotic piece was discovered after removal from its primary context, it is believed to be authentic and to have indeed originated in Mound 2. The effigy has come to symbolize the significance of Morgan. It is stylistically unique for the region and, to our knowledge, is the only piece of non-ceramic Coles Creek art of its kind ever found.”
" There is no naturally-occurring stone in the West Baton Rouge area, so river pebbles of flinty stone found at the Medora site were presumably brought to Mound A from Natchez, Mississippi. The pebbles could have been used in rattles or as raw materials for the chipping of projectile points. These are made of chert – (a compact rock consisting of microcrystalline quartz and similar to flint). Again, this type of stone does not occur naturally in the West Baton Rouge area, and would have been brought in on trade routes, possibly from great distances. A particular type of arrow point used for hunting, called “Alba,” dates to around 800-1200 A.D. and is similar to the arrow points the Plaquemine period Native Americans would have used at Medora. Only seven stone artifacts were recovered."
I found this 11 years ago, caught up in some cypress roots and sand, at the edge of a river.
It always seemed primitive in a way and obviously hand made. A lot of the malachite is missing. The copper color is extraordinary and to me it appears old. I just don’t know how old.
There is an article about Lake Superior copper in some artifact found down here.
many of your posts have refered to ancient artifacts. Have you contacted PaulB36648? He has an interest in ancient trade routes, specifically old world bronze age, prehistorical… is doing research for a book… he is also interested in all ancient trade patterns and gemstone trading for goods and other gems… he could have some ideas that could be helpful in regards to understanding the possibility of ancient trading routes in the Americas…
The door point volcano has not been well studied… I can’t find any petrologic reference to the types of igneous rocks found in this volcano, nor isotopic studies dating the rocks… same goes for the jacksonville volcano… oil company drill cores are mostly proprietary, they don’t release rock samples for study by academics…these hidden igneous rocks need far more study.
what is known about the tectonics of the gulf of mexico date back to the break up of gondwanaland… which took part in three stages, spanning from triassic through late jurassic time… late jurassic to early cretaceous open of the gulf of mexico was associated with incipient rift spreading across the deep gulf,… the geology of the deep gulf of mexico has not been studied well either despite the intensive oil exploration in more shallow waters… the theory of relative hot spot migration from west to east across the southern tier of the US to Bermuda has been not proven… age relations between volcanic centers do not correlated with a progressive old to younger trend… There are two lines of alkalic volcanic centers, one across the northern plains, from west central montana through western south dakota, and parallel line from kansas thru arkansas both of the same eocene age… both lines are highly alkalic, with kimberlite and carbonatite intrusions being present… a number of publications by G. Duke outlines a slab window theory where the low angle subduction of the Farallon plate cause foundering of the plate and ascent of small batch kimberlitic affinity magmas creating both parallel lines of alkalic volcanics. Petrological data match this theory better than a hot spot migratory pattern ony across the southern US…
The trans mexican volcanic belt is an oblique angle subduction zone of the cocos plate under the mexican/north american plate. the subduction zone ends near veracruz which is south of the deep water gulf of mexico…the line of volcanoes cuts east-west across central mexico with the western end being extinct. the cocos plate subduction zone runs parallel to the coast of central america, where the line of volcanos parallels the pacific coast of central american… “super volcanos” are large volume caldera forming eruptions. vei 7 eruptions eject cubic100 kilometers of material, vei 8 the maximum at 1000 cubic km… to 10,000 cubic km…no chance fo a caldera forming vei 7-8 eruption in deep water gulf which has oceanic crust… large dacite to rhyolite eruptions form in thickened crust, either thickened subduction zone crust or continental crust… allowing for large volumn pooling of silicic magma over a time scale of 10- 20 million years…
the deep water gulf of mexico open from an embayment to the present size today during the late stage of the break up of Pangea… crustal spreading by incipient rifting led to ocean floor volcanism in the late creatceous to jurassic… spreading was completed by the cenozoic. salt beds, sedimentation and oil rich shales accumulated during the embayment phase by repeated dry/wet cycles…much like the medditerraean sea is undergoing today, except that the gulf opened while the meditteranean is closing…and will eventually become dry land above sea level…
Steven, you have been amazing in your depth of knowledge.
A lot of what you know is completely over my head. but nonetheless deeply appreciated.
I have not contacted Paul. I’ll do so.
However, here’s a real puzzle for you. The orange stone I can’t scratch with a 9 mohs point, DOES scratch with the diamond bits I have for skinning stones.
Although I realize it’s not a definitive indicator of what a stone is, my Presidium gem tester has been pretty darn accurate on many stones and on this one, it indicates the stone being in the garnet, carneilian, quartz range (so far as I’ll keep testing), so I am really baffled.
Here are some photos of it a bit more polished and over the flashlight so you can see the inclusions and the clarity. I’m really puzzled. Any ideas?
Presidum gem testers are based on thermal conductivity… that is how well a stone conducts heat. Diamonds are best conductors of heat, much more than silver or copper. ID’ing diamond from everything else is where thermal conductivity testing works 100% of the time if the machine is well calibrated. Over all reliability for everything else is 60%… silicate stones have overlapping and very close thermal conductivity bands so they are not good for silicate stones…
they can disininguished from corundum gems as the latter also has a high thermal conductivity… otherwise, Presidium gem testers have limited usefulness.
Instead of trying to polish a hard stone to get an RI, have to thought about just measuring specific gravity? It’s a lot easier to do at home as a screening test… you need a sensitive balance scale, (milligram sensitivity) and weight the stone in air and weight in water… specific gravity by definition is the density of the stone divded by the density of water. Water has a density of 1 gram per cubic centimeter, the weight of the amount water displaced by the weight of the volume of the stone gives specific gravity…for practical purposes it boils down to the difference of the weight of the stone in water versus the weight of the stone in air…all you need is a sensitive balance beam scale and a small plastic net to hold the stone and weigh the stone in water and weight the stone in air, along with the net, when both are dry…quartz stones, of which you will have a majority from a pebble bed will have a specific gravity of 2.65 +/-0.02… If you get an SpG for quartz, you don’t need to go much further… if you think that your orange stone is harder than quartz, do a specific gravity test first… corundum stones with hardness 9 will be denser and heavier than quartz, SG of 3.8 to 4.01, and also be more thermally conductive, which your Presidium will show… by the way, what did your Presidium tester tell you about your orange stone?.. a picture with natural daylight, without the backlighting from the flashlight would be better to see first also. Just from the looks of it, it might be a translucent red carnelian… it would make a nice good quality cab. AAA quality red carnelian sells at $10 to $12 per carat, up to $20/ct at retail… lesser quality for $1.00 per carat…rough is cheap…the price is determined as much by labor to cab the stone… lower labor costs in India and Africa keeps prices for finished cabs low also…
PS: my miswriting: Pangea broke up after it collided with Gondwanaland and made the supercontinent… Pangea… Gondawanaland was already a supercontinent…it’s break up started 100 million years before Pangaea separated, forming the Atantic Ocean… The former consisted of Laurasia in the north and Gondwanaland in the south…The Gulf of Mexico finished opening at the end of the break up of Pangea… the widening of the Atlantic Ocean is continuing today…
the hardness of your point 9 could be off… definitely not an orange diamond by appearance… your presidium would have read diamond by thermal conductivity…
There are cheap materials that are very hard and readily available in any hardware store… a diamond knife sharpener costs $13.00… they are really great for sharpening knives. Because diamond is the hardest on Mohs, diamond coated abrasive stick sharpeners cut into carbon steel knives a lot better than using aluminum oxide (sapphire)… they can be used to test… but will scratch everything… grinding wheels and sharpening stones are made of either alumina 9 (sapphire) or 9.2-9.4 Mohs silicon carbide (carborundum)…simulated diamonds made of the same stuff is moissanite… Emery boards for disposible fingernail files are around hardness 8… natural emery is a mixture of corundum and iron oxides, however it’s been replaced by synthetic which can contain carborundum making it harder… for hardness 7-8, garnet sandpaper fits in at 7- 7.5, then there is quartz 7…which is everywhere, plain silica… for softer, at 6-6.5 is feldspar… which is a soft as you should have to go… anything softer like turquoise or malachite at 5-6 and 3.5-4 won’t be in a pebble bank… the quartz pebbles will grind them up…you won’t likely find feldspar either for the same reason… you can always use these household materials to check against your hardness pencils.
You are a prince. I’ll try to do the specific gravity in a second. I do know all about hardness, etc. but just haven’t trusted myself on the specific gravity test and knowing the refractive index is a pretty specific indicator, along with hardness.
I am wondering, based on the shape of a variety of my stones, if they aren’t Polyhedroid Agate.
They have the exact same shape and so many are banded. Some have sharp edges and some look as if they had that shape, but morphed slightly into less crisp edges.
All right. I can’t get a standard specific gravity. It’s just too difficult for me. I always get a different answer.
However, I’m positive about the hardness. My point is fine. This stone is incredibly hard.
Here’s a group photo of various stones, red one is the one at the bottom.
Adding in, the small yellow one at the very top, fried my Presidium 75.00 pen. When I placed it on the small crack with the whitish stuff, it shot up to diamond and now it won’t move.
So, I’ll try to recalibrate it. If not, I’ll have to wait for a replacement. See what I’m up against? I have just enough knowledge to make me dangerous…Just kidding.
Probably not polyhedral agate. they won’t suvive being waterworn… what’s left are pebbles. Also no geologic formations exposed at the surface for it to form in the lower mississipi… the New Madrid seismic zone is a possible place with failed continental rifting with basaltic magma, however is buried under sediment.
Specific gravity is a good starting point… very easy to do… just google it… contact royjohn on how to set up your own home balance…easy to set up…
The red stone still looks like carnelian or a red agate. If you are sure of the hardness, confirm it with further hardness testing with ordinary home abrasive materials… 9 should scratch the other pebbles, most of them are quartz… if it’s corundum, it should be scratchable with silicon carbide… ordinary grindstones…hardness 9.25 -9.4, a diamond knife sharpener would scratch it easily. Specific gravity for corundum is 4… quite dense for minerals…quartz and other silicates lighter, metallic oxides and sulfide ore minerals much higher…
Presidium testers have to be handled with care… can’t press too hard or too long on one spot… don’t put them into cracks… they are thermal conductivity based and have limited usefulness in identifying silicate minerals as mentioned previously… home testing should rely on three or four different methods to narrow down the range of possibilities.
Back to the drawing board. I’ve been using the Presidium Gem Tester for about 3 or 4 years now. It’s only the second time that has ever happened. Of constant use. I do mean constant.
It’s always the pen that breaks. The machine itself has been worth it. The copper in the pen wears down eventually and gets swallowed into the pen. This is probably my eighth or ninth in 3 or 4 years.
Thanks Steven. You are very sweet to help and offer much good information. Have a great weekend.
But, again, what if they were carried here and then ended up in the water here or close by. They would survive. You have to keep that as a possibility. This was a major trade vector thousands and perhaps longer years ago.
The red one is NOT agate. I guarantee it. It does look like carnelian or garnet. What about Zircon? They have been found on the coast of Florida. But still much harder.
Zircon usually in found in small grains… in Florida it’s in the sand along with rutile… both minerals are resistant to wearing down. Zircons are used to date rocks as they contain uranium that decays into lead. Measuring uranium to lead ratios gives the age of the zircon. The red one is agate in the generic sense, carnelian more specifically…garnet is hardness 7.5…it will get scratched by 9…if you are sure that your red stone is 9… it’s hard to believe that a quartz stone is so hard…do your scratch test using a carborundum grind stone and a diamond knife sharpener to confirm the harness results… don’t rely on any single method to determine the hardness…measure specific gravity…again corundum is very dense compared to silicate stones.
for Presidium testers, do not press hard and do not press long… it will burn up the tip.
If you are just starting as a rock collector, look for local resources… local rock hound clubs are a great way to start. Members of the group have tons of experience and knowledge to share. They know where to find rocks and know what kind they are. If there’s a community college nearby, find the earth sciences people and ask them for help finding resources. If they are willing, they might also help ID your stones for you… Buy some basic books on gems and minerals. I don’t know if the Simon and Shuster Field guides are still in print… Simon and Schuster published numerous field guides to trees, plants, mushrooms, birds, small mammals, you name it… among the publications were two books that are indispensible… the field guide to rocks and minerals and the field guide to gems… the updated Dana’s Mineralogy book is another one to have. Gems are crystals or cryptocrystalline minerals for the most part… these books give you the chemistry, crystal structure, physical and optical properties of many common minerals and gems. Hardness, Specific Gravity, refractive indices are all physical and optical properties. There are a lot more, but you have to start with the most basic first and advance your knowledge base slowly as you gain experience. Reading and study is mandatory to gain knowledge. Having a support system of local resources including professional jewelers and rock hound clubs is also essential. Gemology is both a science and an art. The science part can be overwhelming unless you have a college background with physics, chemistry and some mathematics… the art part comes from experience and sharing experience with others in gemology…nonetheless, some of the basics of science can be obtained from reading the reference books I mentioned. My interest isn’t as much in pretty rocks per se… I have collected them but good specifmens are too hard to find… I have collected over the years, have have found a few museum quality specimens… I need more rocks like a hole in the head… I will be selective in donating them to local museums and geology departments where they will be displayed and not hidden away in cardboard boxes in the basement. My interests have shifted to how minerals and rocks are created by earth processes… how ore deposits and gem deposits are created over millions to billions of years by the earth… the level of scientific knowledge required to read the academic literature is still not completely within my grasp… I am not a trained geoscientist but a scientist in another field… I have to return to college chemistry and physics over and over, and also read textbooks for advanced undergraduate geology classes for petrology, phase equilibria, isotope geochemistry and partitioning of trace elements and isotopes, chemical thermodynamics under high pressure and temperature, to understand the current literature…The conference on rocks that I go to are PhD symposia… I can understand most or all of it from a qualitative standpoint, but not quantitatively, as it does require advanced mathematics and advanced physical chemistry… If someone asked me to calculate the Gibbs free energy of mineral reactions under specific high temperature and high pressure conditions, I wouldn’t be able to on my own…but I still am able to follow the mathematical arguments when they are presented. My long term goal is to be able to do it myself. I am considering taking a degree in geology and geochemistry but am too busy in retirement to do so just yet…other priorities take precedence but I still read and constantly look things up on the internet for information…
The creation of gemstone and ore deposits requires a ten thousand fold increase or more in the average crustal concentration of certain elements. Lithium, Beryllium make for gem beryls and tourmaline, florine for topaz… corundum stones with hardness 9 (sapphires, rubies) require unusual geologic circumstances for them to form. With the exception of quartz, most gemstones and all metal deposits require enormous volumes of rock (mountain ranges) and millions to hundreds of million of years to effect concentration of trace elements and rare elements to form ores and gemstone deposits… it happens because the earth is dynamic and plate tectonics are active processes…the earth is 4.5 billion years old and has had a lot of time to evolve and a lot of time to move huge masses of rocks- continents- for these concentration processes to work…
It gives you a sense of wonderment… cheers! and good luck with pursuing further study… I hope you find the resources you need. They are all available if you look.
the second photo shows your red stone and another one that looks like a very nice agate. the banding pattern in it will make a very nice cab… you also have banded agages in the bowl or rocks in the last photo… these also will make for nice cabs…
continue to show photos as you like but please start studying up on rocks and minerals… it will open a new world of insight into what you have.
also send a picture of your specific gravity measuring device. If you can’t get a reliable SG measurement, a series of pictures of your scale might help others find out why you can’t, and where the errors in measurements could come from.
Okay. Now I’m insulted. I have many books, which I have read and studied, as well as in the field knowledge so to speakl.
I am asking for nothing in this thread, other than to enjoy the photos. If you have any insights which are less snobbish, ignorant and completely devoid of imagination or probability, then please feel free to contribute.
For the record, the major rivers down here carry an incredible load of sediment and are quite capable of transporting stones with less tumult.
Some people enjoy these stones because they are incredibly beautiful and a wonder of nature.
no intent to insult, so sorry for that and so sorry if you misintepreted my post… reading and studying is great…it’s a life long endeavor… I’m glad that you have done so and please continue… I’m also a learner, not by any means an expert, my perspective is geologic and not gemmologic…
the trouble with photos is that they can’t tell the whole story… nearly eveyone will say that photos aren’t enough for an ID… which is also why I can’t tell what anything is with a photo without additional data. You river rocks are very pretty and as I’ve said repeatedly will make for nice cabs… some if not most of them look, from the photos alone to be agates, cryptocrystalline quartz. Transforming them into great looking jewelry stones is not easy… I’ve cut numerous prairie agates and hills agates with a slab saw looking inside the rough stones for good colors and patterrns… the vast majority didn’t show much worth cabbing… but a few did… the one stone that has surface patterns that you showed along with the red one that is the hard mystery stone has a lot of promise for making into a jewerly stone… I’m still wondering wether you have ID’d the hard red one… if it’s corundum, you could have something worth far more than the others… let everyone know when you find out what it is.
All of your river rocks have some polish to the surface… even though most of the river bottoms in the lower Mississipi is mud, many of the stones did not originate where they were found but were washed down from higher up the in mississippi river drainage… episodic floods move tons of rock from higher up in the drainage system… as the largest US river, upstream sources can come from almost anywhere in the drainage system… the water sorts them by specific gravity… lighter stone get carried further with heavier ones dropping out earlier, which is why your red hard stone is so interesting… even if there’s no sand where you are, agates and chalcedony have to be weathered out of their host rocks to be set free… those host rocks will contain quartz sands and other hard mineral grains that do the shaping and polishing… mud and mud rocks downstream contain a lot of clay minerals… these are too soft to abrade quartz…
Your last picture of stones in a plate shows your blue green stone, and next to it to the right, what looks to be a banded agaite stone… the red stone at 2 o’clock looks very promising… the brown banded stone at 4 o’clok also looks like a potentially nice one if cut and polished into a cab… the one I like the best is the one in the picture second to the last, next to your red hard mystery stone…the eye patterns and concentric rings make it an agate that is a gem agate…that one, if ground into a cab will be valuable, so far as quartz stones can be… grinding cabocons is an art… you can lose some of the patterns if they are superficial and ground away… on the other hand, there could be pleasant suprises beneath the surface…it and some of your other stones could be worth taking to a lapidary for further assessment, if you don’t have the equipment to grind them and cut them yourself… an experience lapidary will know how to cut and polish them to bring out their full potential as gemstones… transforming rough into jewerly material adds value…setting cabs into jewerly adds even more value…as a jeweler, the added value is a lot more than rough… however, only if you can do some of it yourself… otherwise paying a professional lapidary and jeweler to set the stone won’t make you money…at least in the short run…
Although I am advocating to selected the best ones and turn them into jewelry, you may be content to just collect them…that’s great enough, especially if you can find some very nice rough…continue to collect them… it’s a great hobby, especially if you can go along with a local rock hound club…
Best of luck in finding more. and finding the local resources than can help you with ID…
The trade route theory makes a lot of sense. I research ancient trade routes and although my focus has not been in that part of the world, the whole south central US was a climate refugia and as a result, for long periods of time pre-contact, it was like the Med during the last ice age, a place of resettlement of huge numbers of cultures displaced by climate disruptions, and as a result, a massive region of trade. The same was almost certainly the care for that region. Note these periods last millennia, and since the last major epoch during which these large scale displacements occurred, there has been a huge amount of genetic admixture and replacement, so when considering artifacts from the distant past, it’s essential to keep in mind that those who produced/traded them may have been very different from modern humans in terms of belief systems, culture, cultural expression, and even genetics. In other words, what counts for a “gemstone” , “effigy”, or motif/technique of expression today, was regularly very different in the deep past, and our brains are not wired to see a lot of things we don’t already have a visual reference for. A lot of worked artifacts recur, and include dimensions of expression that we deem ‘natural’, when in fact they are worked (we can’t see the signal from the noise absent a baseline reference to see it as such). My point is, such trade dis occurs, very broadly for millennia, and just because the surviving artifacts don’t something a Greek or Roman would covet/trade (an intentionally crude benchmark), doesn’t mean it wasn’t both human worked and traded.
but nonetheless deeply appreciated.
