❓Your Mineral Identification Questions answered here
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Looks like slag to me. Mackka
Also my suspicion. It would help a lot if people were willing to give locations - in most cases there is no logical reason not to.
Hi. This rock was given to me many years ago when I was a little girl by my grandfather. He told me to look after it and said it was a museum piece. Unfortunately he has passed now.
I sincerely hope i am 100% wrong, but, i think your grandfather might have been doing exactly that, being a grandfather as we do with grandkids, i.e. telling porkies. Mackka
Lols. I have considered that but is it possible slag be that spectacular to look at. Is there a test I can do to confirm it’s not maybe?
To be absolutely sure, contact your state museum‘s mineral identification service And email them pictures of your specimen. They may ask you to actually drop it off to them for inspection and tests if they are unsure. It may take some time depending on how much work they have but they will return it to you after they have finished the identification.
Be prepared though for disappointment.
That is the lot for all us prospectors.
Be prepared though for disappointment.
That is the lot for all us prospectors.
That’s ok. I have a few different rocks.
Mod edit:
Moved the post re: tumbler for boulder opal to it's own seperate thread.
https://www.prospectingaustralia.com/threads/tumbler-for-boulder-opal.40059/
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It’s an amazing specimen to look at magnified.
I think antimonite is just an old and no longer recognized name for stibnite.
Stibnite is fairly easily identified, as it has a Moh's hardness of only 2 so can be scratched with your fingernail.
However I don't think that is what it is...
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The rock is very hard. I tried to grind into the cnr of the rock and I snapped the disc.
I tried to grind a cnr off, to show u in a few more pics attached only I snapped the blade off the grinder. I assume the rock is very hard.
It has been tested for different carats of gold only the rock came back inclusive saying it was positive in all tests.
I have many pics and the rock looks and reflects different in every pic.
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What do you mean, “ it has been tested for “Different” carats of gold and were the tests “ inclusive” or “ inconclusive”? Mackka
All tests were positive.
Ouch - I hope no one made you pay for those tests? If so, you were had I feel. Youb wanted an analysis foir gold content not carats. As you said, too hard for carrots or stibnite).All tests were positive.
I suggest you change your analyst - and perhaps ask about such things here before doing them. People here are great at heading off mistakes in advance.
I should clarify - karats simply tell you whether a set amount of silver and copper are analysed with the gold - so there are only a few possible numbers and any if them have gold, alloyed purposely to a specific composition by a jewller/metallurgist. All of them have gold - strictly it is meaningless to say that a sample has x karat gold, y karat gold and z karat gold because it can only be one of these. . What you want is usually g/t (grams per tonne) or ppm (parts per million) of gold, which is a sliding continuous scale and gives one unique answer - the amount of gold present in the sample. So a gold ring will be manufactured to 9. 12 or 24 karat (only one of these for one ring) - the lower the karats the less expensive the ring. It is a measure of the other metals alloyed with the gold - intentionally, in a specific ratio. Also, yellowness of gold is not a reliable indicator because copper can increase the shade of yellow in a ring with less gold - the hallmark stamped on the ring is its certified number of karats (same for any other gold jewellery). .
Fire assay is most accurate as long as you have an adequate sample size, although I often use a cheaper method (usually something like AAS) if I just want an approximate value (i.e. to know significant gold is present). However the error can be 30% in that case (I once ran a series of samples, each by both methods, and that was the error I found). The cheaper method is more of a problem if a lot of some sulphide mineral(s) is present - it is more accurate where you are dealing with less than a couple of percent sulphides in white quartz and where the gold is free, not locked up inside the sulphide minerals.
I am mentioning this for others as well - many people use the wrong assay method or the wrong sized sample for the material they are assaying.
https://www.onecklace.com/tips/karat-gold-understanding-gold-purity/
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The smelting process creates not only fancy crystal forms like needles but also minerals that are not known to occur naturally. Here are two examples (I don't think either are what you have).
Smelter products often form fine needles - this is caste iron
this is lead smelter slag (needles are calcium phosphate)
The needles in smelter products usually result from it being suddenly quenched to soild from a liquid state, so it does not have time to crystallize properly.
Smelter products often form fine needles - this is caste iron
this is lead smelter slag (needles are calcium phosphate)
The needles in smelter products usually result from it being suddenly quenched to soild from a liquid state, so it does not have time to crystallize properly.
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