How do I identify my stones?

Hello - Thank you very much for admitting me. I might not be in the right type of forum; however, beginning my quest with the good folks at the prospecting level is a good start, before heading for a jeweller. Some 25 years ago (I’m now 66), I bought a necklace, knotted with a silk string, containing 2 small crystal ‘towers’, 4 small tumbled Amethysts, and 3 ‘uninteresting’ glassy stones the artisan called ‘Killiecrankie Diamond’. It meant nothing to me, but the name was kinda querky and stuck in my memory. The silk (cotton?) thread has become a victim of moths, so I rescued the stones from the unravelling piece. From memory, the artisan who made the necklace either fossicked herself, or got the stone from a fossicker.

I’ve always wondered how a prospector can tell a pebble from a semi-precious/precious stone.

Cleaning out the box with decades of accumulated ‘stuff’, I came across these stones again. Remembering the name, ‘Killiecrankie Diamond’, I thought it might be worth finding out whether they really are what I have now googled to be Flinders Island Topaz. One stone is blueish and quite angular, the other is yellowish, with rounded off corners, the third is entirely clear, as smooth as a mirror, and shaped like jellybean.

Someone said that, given the ‘artisan’ setting of a knotted string, they’re probably quartz.

Before I put them in the basket of kids’ marbles, I would like to identify them properly.

I have taken photos and upload one (as that’s all I’m permitted to upload as a newbie). If anyone knows what a real Killiecrankie Diamond looks like, or can point me in the direction of the means of identifying the stones, I would appreciate it.

Thank you.


Nice stones, very clear

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Thanks, Nigel - I like them, too; that’s why I’d like to find out for sure what they are.

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It’s not a proper test, but topaz feels cooler than amethyst/quartz when you put it on your lips.

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:slight_smile: I shall kiss my stones and see what my lips make of it :slight_smile:

What a nice way to ‘test’ them.


Now here’s an odd thing … I did as suggested by dhawley, half thinking someone was pulling my leg (I’m always up for a bit of joshing), and am quite astonished.

When, at first, I put both - the small quartz cristal ‘spike / tower / shard’ and the blue stone - to my lips, they were both as cool as each other, but then the crystal soon attained the same (or similar) temperature as my fingers, while the blue stone did not, it stayed cool much longer. When I repeated it with the second crystal shard, and the yellow ‘diamond’, the same thing happened.

I’ve got to ask: Is this a scientific method?

I still don’t know what to make of the jelly bean ‘diamond’, tho …

Also: if a prospector would find these three stones (as presented in the photo) in a creek, prospecting for stones, what would be their first step to identify them as the famous ‘Killikrankie Diamonds’, or something else. I have to admit, if I picked them up, I’d say they were just pieces of some bottle glass that got discarded at some time in the past, and had worn down to such a shape - that still doesn’t account for the jelly bean ‘diamond’.


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Certainly “looks” like Topaz; get one of your amethysts and see if it will scratch any of the 3 stones; if no scratching then they are above quartz on the hardness table which will indicate the realm of topaz.


Hi PatHogan - I took my cluster of dark amethyst, with heaps of pointy and very sharp teeth (because the ‘rounded’ rock back gives me good grip), and one by one scratched the ‘diamonds’. There were ‘trails’ of light coloured dust where I scratched back and forth, with some pressure - when I wiped it away, there was not a single scratch on any of the sides/surfaces of the 3 ‘diamonds’, but the amethyst teeth had lost their sharp edge. So - quietly confident that they are what I bought them for: Flinders Island Topaz? Even the ‘jellybean’?

How can ‘Killiecrankie Diamonds’ be so different (e.g. square-ish/multi-sided/striated), and another one as smooth as crystal glass and shaped like a jellybean?

I like this process …

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It looks like the clear one has been polished in a rock tumbler and the other 2 are in their natural state as they came out of the ground. I think topaz grows as 4 or 5 sided crystals then breaks into slices as the host rocks break down then sometimes gets washed into a river and tumbled until it turns into jellybeans.


Thank you so much for the explanation, dhawley; I’ve never turned my hand to any prospecting activity, and at my tender age I won’t start now, so the ‘what to look for’ has always been a mystery to me. I have some pretty stones that have been tumbled, are shiny, and are souvenirs, and store-bought (I like colour, dislike ‘real’ diamonds, because they have no colour, which is why I never paid any attention to my three stones) and can understand the polished jellybean now.

I have now read up on the difference between quartz crystal and topas … but all the technical jargon means not much, except that there is a difference in hardness, which I found out by scratching. … One very informative website said: “The crystal system of topaz is orthorhombic whereas the crystal system for quartz is hexagonal.” … I tried to get my head around ‘orthorhombic’ … doh …

My favourite is the blue-ish one. I think I’ll choose that one for the planned ‘eclectic’ pendant.

Given they stayed cooler than the quartz when ‘kissing them’; that I gave the ‘diamonds’ quite a bit of a beating by scratching them with the sharp teeth of the amethyst, and the amethysts lost their points/sharpness, but no scratch on the ‘diamonds’; the time that passed since I purchased the necklace with the stones in it; and that they look much like stones I found on google images, the confidence in them being said ‘diamonds’ has risen quite a few knotches again.

Is there anything else I can do?


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:ok_hand: You have done well. Natural processes or no process at all will determine crystal shapes, as in a defined crystal will have suffered no weathering down to a smooth, rounded pebble that has been polished by weathering through water, grit and movement. It looks as though you have 3 topaz with a hardness of 8.5 on the mohs scale, while other topaz has a hardness of 8 .

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Really chuffed :+1: … when you say 8.5 as opposed to 8 on the mohs scale (I’ve heard of it, with topaz having 8) - is this good or bad? Probably good because it is .5 higher than 8.

I have a facetted stone, golden citrine, or golden topaz. Can I do the same amethyst scratch test on the back of it (not trying to ruin the face of it)?

This stone caper is fascinating …

“Is it good or bad” - now that is an involved question but my answer is, it is an identity of the stone. One could probably assume that a stone with a greater hardness would not break as easy, when hit with a hammer as a stone that has a lesser hardness rating but that is not a relative indicator ( I will leave you to search the factors regarding hardness via your search engine). The crystalline structure of topaz 8.5 is an identifier but the cutting of these stones can be wrought with failure due to the lattice structure of the crystal, but they do polish nicely. However, other Tasmanian topaz is recognised as the best faceting material bar none, with a hardness of 8, but the mineral composition of the stone sets it apart from other topaz. For instance, O’Briens Creek topaz cuts like butter while Moina topaz cuts like steel, both being an 8 hardness.
I would not scratch the pavilion of a faceted stone unless you are prepared to repolish it, but yes, you can.

Hello PatHogen - Thank you so much for all the explanations - I truly appreciate it. I can definitely understand how things to do with stones aren’t straight forward; I know how to work with wood, timbers, and one cannot treat all timbers the same way in any given situation.

Wow! I’m happy to accept my 3 ‘diamonds’ as the Flinders Island topaz I bought them for, and leave well enough alone. The ‘who’ of where they came from - in a roundabout way - also gives me confidence that they are what the artisan who created the knotted knecklace said they are.

This has been an enjoyable and educational small thread - thank you so much for indulging me, it helped a lot.

Here is another angle of the blueish stone - photographed before I scratched it with the amethyst without scratching it - and the surfaces are still like this.

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PS - no, I won’t scratch the golden stone …

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That’s still got a beautiful angular, crystal shape. My suggestion would be to find a gem cutter to polish the flat faces and leave the rounded sections as they are. This would give you a view into the stone without taking away from the natural feel.

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Hello dhawley - now you’re saying what I’ve been thinking. I didn’t follow that thought any further because finding a gem cutter up here in the north-west of Tas seemed a little impossible. Now I’ll make an effort to find one. I found a skilled jeweller in Burnie who is repurposing some old jewellery for me - beautiful work. He will probably be able to point me in the direction of someone who can do it.

Exciting little project …

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PM me re polishing a face on your stone. I am near Penguin.


I’ll PM as soon as I find how and where the PM button is … pause … 10 minutes and I can still not find where to write a PM - I’ve found ‘messages’, where the bot greeting sits, but no writing window to write a new PM … doh … PS, I’m in Wynyard.

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Yes, topaz has a higher density and thermal mass, and better thermal conductivity than quartz.

This means that it takes more heat from your body to heat up a piece of quartz than a piece of topaz to body heat, which in turn causes it to take more time for the bit in contact with your skin to equalise with it in temperature if it is topaz compared to quartz.