FMF - Friends of Minerals Forum, discussion and message board

[Paul]

I've recently aquired a Mineral specimen collection with a few hundred specimens in it, over the last few weeks I've been slowly identifying the pieces in the collection that are no longer catalogued with the help of local rock club members etc, but the collection is large and there are some very unique items in it.

Any help to identify or confirm identification of these specimens would be very much apreciated, an indication of value would also be apreciated.

36&37. The first two images are of the same specimen it is covered in what I believe are calcite crystals on a cuprite matrix, the yellow crystals are unknown to me.

39. Am I correct in saying this is calcite?

43. Orange River Quartz on Matrix

46.Gauderfouclite?

50. Green Kyanite?

53.Chalco Pyerite & ?

54. Rhodocrosite or Rhodonite?

55&56. Calcite With Cuprite Crystals & ?

[Paul]

Here are a few more.

59. Azurite on Matrix?

61. ?

63. ??

70. Dioptase

78&84. Green Tourmaline on Calcite?

82. Baryte?

86. Some Form of Quartz?

89. Baryte?

[Montanpark]

Hi,
i´ll quickly try to get some of them i think i can identify:

59: azurite seems to be correct (maybe moroccan)
61: looks like stichtite (maybe Barberton area, RSA)
70 dioptase (probably Tsumeb)
78 & 84 both tourmaline with quartz
82 looks like Torbernite from Congo to me .. careful, radioactive
43 quartz
36 & 37 .. the yellowish could be mimetite, looks like Tsumeb stuff
50 actinolite
54 cobaltoan calcite or dolomite rather than rhodochroslite ... there is apparently some greenish mineral associated (malachite?), could be from Congo
I have some guesses also for the other specimens but the pictures aren´t clear enough.

in a hurry
cheers
Roger

[Paul]

Thank you for the help, I'll try to take a few clearer pictures of the others.

You are probably correct in your assesment that some of the specimens are from the Tsumeb, there are a large number of known specimens from that region in the collection.

[nurbo]

Hello,
63 looks like it may be Seraphinite it looks like ones Ive seen from the Urals
db

[Paul]

Thanks Nurbo,

Some more info on Specimen 63.

It's Hardness is soft enough to be scratched with a finger nail, Streak test reveals black streaks in a unglazed tile, White inclusions seem to be quartz, with a streak of what appears to be calcite.

I'ts also been identified as possibly star tourmaline, but I'm sceptical of that name.

The rock is heavier than it looks and seems to have minute pyerite inclusions.

[Paul]

Another Angle of Specimen 63

[Jordi Fabre]

46.Gauderfouclite? = Gaudefroyite from Kalahari manganese fields, South Africa: https://www.mineralatlas.com/mineral%20photos/G/gaudefroyitecp.htm

Jordi

[Paul]

And a closer image of Specimen 86, I suspect that this is Needle Quartz, I'm not sure what caused the coloring.

[Paul]

Thanks Jordi.

Yes I mistyped Gaudefroyite, it's very heavy for it's size and extremely hard. Under a microscope, it appears to closely match the specimens identified as coming from the wessels mine in Kuruman.

[nurbo]

re no 63, if you can scratch it with a finger nail it may be Seraphinite (or Clinochlore), that has a Mohs hardness of around 2.5 which is finger nail scratchable. Maybe other more knowledgable members can confirm what it is, but one thing is for sure though it isnt tourmaline which is unfingernailscratchable
db

[John S. White]

86 looks like iron oxide impregnated quartz (eisenkiesel) fro Suttrop/Warstein, Sauerland, Germany. It is very distinctive.

[Montanpark]

I don´t think this is a Suttrop quartz. Pauls assumption that it is from the Orange River area is more probable ... particularly as there are obviously a lot of African specimens in the collection.

53 may be a pyrite/chalcopyrite ore with a silicate (have seen such specimens with dark actinolite from Italy for instance)
55 looks like cuprite (1st pictue in the vig) with calcite and malachite/plancheite on matrix. Presumably Congo.
89 looks like a baryte from Rosh Pinah, Namibia, got a few of this pale kind in 2005 also. But this is just a guess as the picture isn´t that clear.

cheers
Roger

[John S. White]

I was referring to 86 which I am quite certain is a Suttrop quartz, I have an almost identical one in my collection and it has been confirmed by several German collectors. The likely Orange River quartz is 43, and I have one of these in my collection as well. Come on, let's not make things any more confused than necessary.

[Montanpark]

John,
sry, my fault, i meant the reddish one 43. But i find it hard to tell by only the picture that 86 should come from Suttrop. Quartzes like these with iron oxide inclusions are widespread (and not only in Germany ) ..
but of course it is possible

cheers
Roger (writing from Mainz, GER)-