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07 Jun-04:01:19 Re: from where is this sulphur?. Could it be from italy? (Tobi)
07 Jun-03:35:32 Re: collection of sante celiberti - a mineralogical trip through italy (Tobi)
07 Jun-03:01:02 Re: collection of michael shaw (Tobi)
06 Jun-14:26:08 Re: collection of sante celiberti - a mineralogical trip through italy (Sante Celiberti)
06 Jun-12:00:07 Re: help needed for locations (Dany Mabillard)
06 Jun-10:10:55 Re: collection of philippe durand (Philippe Durand)
06 Jun-04:27:28 Re: any interesting minerals from ukraine? (Riccardo Modanesi)
05 Jun-17:22:49 Re: help needed for locations (Sante Celiberti)
05 Jun-16:32:01 Re: help needed for locations (Dany Mabillard)
05 Jun-16:29:24 Re: collection of sante celiberti - a mineralogical trip through italy (Sante Celiberti)
05 Jun-16:25:39 Re: help needed for locations (Dany Mabillard)
05 Jun-15:06:39 Re: help needed for locations (Sante Celiberti)
05 Jun-14:52:51 Re: help needed for locations (Sante Celiberti)
05 Jun-14:45:28 Re: collection of michael shaw (Michael Shaw)
05 Jun-14:28:52 Re: from where is this sulphur?. Could it be from italy? (James Catmur)
05 Jun-14:00:18 Re: help needed for locations (James Catmur)
05 Jun-13:58:50 Re: from where is this sulphur?. Could it be from italy? (Jordi Fabre)
05 Jun-13:50:34 Re: from where is this sulphur?. Could it be from italy? (James Catmur)
05 Jun-11:24:53 Re: help needed for locations (Dany Mabillard)
05 Jun-11:24:43 Re: from where is this sulphur?. Could it be from italy? (David)
05 Jun-11:12:15 Re: any interesting minerals from ukraine? (David)
05 Jun-06:52:32 Re: collection of sante celiberti - a mineralogical trip through italy (Tobi)
05 Jun-06:43:00 Re: any interesting minerals from ukraine? (Peter Lemkin)
05 Jun-06:40:34 Re: from where is this sulphur?. Could it be from italy? (Tobi)
05 Jun-03:08:20 Re: from where is this sulphur?. Could it be from italy? (David)

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  Topic: Weird face in quartz
Reef

Replies: 32
Views: 29456

PostForum: Minerals and Mineralogy   Posted: Feb 06, 2020 11:36   Subject: Re: Weird face in quartz
Sometimes a rhombohedron (012) is replaced by a ditrigonal scalenohedron. Together with {012}, on the vertex there are occasional faces from (103) to (1.0.11), down to the pinacoid (001).
I apologize ...
  Topic: V-Twin Found in Washington
Reef

Replies: 7
Views: 5576

PostForum: What is it? - Where is it from?   Posted: Feb 05, 2020 04:49   Subject: Re: V-Twin Found in Washington
In the Sella law twin, the indicated faces of the rhombohedrons must be parallel
  Topic: "Frosted patterns" on the faces of Quartz
Reef

Replies: 10
Views: 8330

PostForum: Minerals and Mineralogy   Posted: Nov 30, 2017 05:23   Subject: Re: "Frosted patterns" on the faces of Quartz
A request, who has similar samples with a "dendritic" pattern, publish a photo.
A few more photos.
  Topic: "Frosted patterns" on the faces of Quartz
Reef

Replies: 10
Views: 8330

PostForum: Minerals and Mineralogy   Posted: Nov 27, 2017 12:59   Subject: Re: "Frosted patterns" on the faces of Quartz
I do not know how this is formed, but interesting and beautiful. In my opinion there is no etching here. Whims of skeletal growth. Host rocks: calcareous sandstone, marl, calcite, dolomite. The veins ...
  Topic: "Frosted patterns" on the faces of Quartz
Reef

Replies: 10
Views: 8330

PostForum: Minerals and Mineralogy   Posted: Nov 27, 2017 05:45   Subject: "Frosted patterns" on the faces of Quartz
I would call this dendritic growth. But it is believed that quartz can not have it.
The sizes of the samples are mainly up to ~ 15 mm.
Locality: Alatau, Bashkortostan Republic, Southern Urals, Ura ...
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 21, 2017 11:20   Subject: Re: Rarest quartz twins with inclined axes C
Another law of twinning quartz under the working title "Ural". Theoretically, this law has already been predicted. Samples that confirm this law have not been found so far. It is an analogue ...
  Topic: Weird face in quartz
Reef

Replies: 32
Views: 29456

PostForum: Minerals and Mineralogy   Posted: Nov 15, 2017 11:10   Subject: Re: Weird face in quartz
Hello, Pierre! On your photo, a parallel splice, at least 3 crystals. You see a rhombohedron of the third crystal. Such composite crystals an everyday occurrence.
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 09, 2017 11:25   Subject: Re: Rarest quartz twins with inclined axes C
... So first, my question is how were these angles measured?
If there is a parallelism of faces and edges, as in diagrams, then there is no doubt. It will be a twin. It remains only to make sure of ...
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 08, 2017 11:38   Subject: Re: Rarest quartz twins with inclined axes C
Josele, good luck with your search !

Reichenstein - Griesernthal law twin
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 04, 2017 12:50   Subject: Re: Rarest quartz twins with inclined axes C
Friedel Law Twin
Angle 90°
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 04, 2017 12:01   Subject: Re: Rarest quartz twins with inclined axes C
Zwickau law twin
Angle 42°17'
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 04, 2017 11:56   Subject: Re: Rarest quartz twins with inclined axes C
Breithaupt law twin
Angle 48°54'
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 04, 2017 11:02   Subject: Re: Rarest quartz twins with inclined axes C
I agree, pleasant twins.
The costs of machine translation. The main thing is for people to understand what the conversation is about.

Continue..
Goldschmidt law twin
Angle 47°43'
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Nov 03, 2017 05:26   Subject: Re: Rarest quartz twins with inclined axes C
Can anyone confirm or disprove this opinion (previous message)? If such splices (a prism to a prism) do not contradict the laws of twinning, then the circle of search for twins will expand. And we can ...
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Oct 31, 2017 09:29   Subject: Re: Rarest quartz twins with inclined axes C
Hi Jordi. Thank you. Overlooked.

Another variant of the arrangement is in the twins of the Japanese type.
There was a splicing of prisms. A small crystal is located on the prism of a large crysta ...
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Oct 30, 2017 15:51   Subject: Re: Rarest quartz twins with inclined axes C
The concept of two equal individuals in twins is wrong.
In the laws of twinning, there is no condition for the relative dimensions of subindivids.
Here are some examples.
Japan Law Twin
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Oct 27, 2017 07:48   Subject: Re: Rarest quartz twins with inclined axes C
Pete, thanks for the corrections. About the schematic drawings, a little prehistory. Two years ago I became interested in quartz twins. According to the book K. Frondel at first absolutely did not und ...
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Oct 26, 2017 10:37   Subject: Re: Rarest quartz twins with inclined axes C
One of the most favorite types of twinning
Disentis law twin
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Oct 26, 2017 08:10   Subject: Re: Rarest quartz twins with inclined axes C
Pete, thanks for the clarification.I did only visualization of these twinning laws. So far, nothing new has been proposed. In the literature there are only descriptions or mentions of these laws, and ...
  Topic: Rarest quartz twins with inclined axes C
Reef

Replies: 42
Views: 27445

PostForum: Minerals and Mineralogy   Posted: Oct 25, 2017 11:55   Subject: Re: Rarest quartz twins with inclined axes C
Seedorf 1 law twin
 
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