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EmmaP
I think I have found a lump of crystal can anyone identify what it might be? Many thanks. Click image for larger version - Name: IMG_20180909_095026.jpg, Views: 34, Size: 1.39 MB Click image for larger version - Name: IMG_20180909_094850.jpg, Views: 35, Size: 1.25 MB Click image for larger version - Name: IMG_20180909_094926.jpg, Views: 35, Size: 1.40 MB
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Dirty Pete
From the pic I'd guess calcite. But you'd need to mention where you found it, its density, its streak, how hard it is on Mohs scale (google it) and if it reacts with acid to get a more definitive ID.
If you can scratch it with a metal nail easily and you get bubbles generated when in contact with heated vinegar then its probably calcite.
Pete.

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EmmaP
Hi Pete. It seems to be a 4 on the Mohd scale. I did the vinegar test but there wasn't any fizz but a few white spots appeared. The mineral seems to be clear and merky with an orange tinge. It was found in Highcliff Dorset.
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Dirty Pete
Calcite won't 'fizz' vigorously with vinegar but with a blob of vinegar on the mineral surface you should be able to see tiny bubbles develop at the interface with a hand lens or magnifying glass. Try grinding some of the mineral to a powder with a file and then adding vinegar. If you are sure there is absolutely no reaction and your hardness value is accurate..ish I'd guess dolomite. (dolomite will react slowly with 10%HCl and fizz with 50% but I guess you haven't any neat HCl). Without any other evidence all you can say is that you have a clear to off white mineral (assuming the clear and off white are the same mineral) with a hardness of around 4. 

Pete


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