I picked up this rough in West africa in a river and I have since sent it to GIA for evaluation, once I returned back to USA. We think its Garnet, if its ok with the rules of this board my I post some pictures?
I hope to hear from GIA this week, but i was wondering if any experts could eye it.
I am asking permission, because last time I posted on another website and they banned me. It was mean and I still to this date dont know why. So I am ready to post the rough once a Mod says ok.
The one that looks like it has a darker brown coating on it looks particularly like an agate to me.
Garnet just doesn't look like that.
Unfortunately, none of the stones show any crystal faces so it's pretty much impossible to say anything more than that they are an orange material of some sort without having them in hand. They really could be anything.
There's a fair amount of salting that can go on at mines. Literally every trick in the book goes on - Tibetan Andesine anyone - and the closer you get to the source the more likely you are to encounter synthetics.
based on these pictures you just posted then they look more like garnet than carnelian, but its possible they are carnelian. I personally collected them in a river in Nigeria on a trip we did for some gold exploration.
I would say that the gems are a water warn and tumbled by nature.
Most garnets are zoned; in fact only rarely are they not zoned. But the zoning may not be visually obvious. The most common way in which garnets form is through metamorphism of sedimentary rocks. The core of the garnet, which grows first, will have one chemical composition. As it grows the composition of each layer of the garnet changes as the garnet gets larger. Geologists who analyze garnets using an electron microprobe are able to perform chemical analysis of spots as small as one micron (one thousandth of a millimeter!!). With that technique they are able to make a chemical map of the garnet by analyzing dozens or even hundreds of spots on a single crystal. Commonly these analyses reveal that the garnets (usually amandine) have cores rich in magnesium and rims rich in iron. Some garnets do have visible color bands, but others require microprobe analysis to “see” the zoning.
Bearing in mind that all we have to go on is your pictures, I have to say I am firmly in the carnelian camp, especially the picture called orange red 1.jpg
I want to thank everyone who has taken the time to comment on these not so great photos. I appreciate your feedback and I may ask a lot of questions, but I am very appreciative.
You see how many of your pics look just like the carnelian in Vapids pic(the very back stone).
Great pics, by the way Vapid..well done in comparing
What country did you find them in?
The difference between carnelian and garnet are pretty dramatic. Carnelian has a fairly low refractive index and is never water clear. Garnet on the other hand, has a substantially higher refractive index and only has significant value if it is water clear and facetable. The bottom line as far as value is that if the stone is not water clear and facetable, then you may as well treat it as a carnelian since the values of either stone in a translucent grade are similar. I would certainly have someone with the means to test the R.I. of the stone do so, just so that you can be sure of what you have.
That would be carnelian. Note the greasy smooth texture. Go to wikipedia(carnelian) and the very first pic on the right..the left specimen in that pic looks like it was taken from your latest photos(the round one)..with little more light added to it