We use cookies to show content based on your preferences. If you continue to browse you accept their use and installation. More information. >

FMF - Friends of Minerals Forum, discussion and message board
The place to share your mineralogical experiences


Spanish message board






Newest topics and users posts
16 Jun-23:46:22 Re: don lum collection (Volkmar Stingl)
16 Jun-22:46:40 Re: don lum collection (Don Lum)
16 Jun-21:02:18 Re: the mizunaka collection (Am Mizunaka)
16 Jun-21:00:39 Re: the mizunaka collection - quartz (Am Mizunaka)
16 Jun-16:02:19 Re: collection of sante celiberti (Sante Celiberti)
16 Jun-09:46:06 Re: favourite quartzes? (Eck Noch)
16 Jun-09:18:57 Re: favourite quartzes? (Eck Noch)
16 Jun-08:56:20 Re: a mineralogical trip through the states of usa - indiana (Bob Harman)
16 Jun-08:26:28 Re: favourite quartzes? (Bob Harman)
16 Jun-05:22:04 Re: collection of volkmar stingl (Volkmar Stingl)
16 Jun-05:16:36 Re: the mizunaka collection (Volkmar Stingl)
16 Jun-03:54:43 Re: collection of volkmar stingl (Volkmar Stingl)
16 Jun-03:38:45 Re: collection of volkmar stingl (Tobi)
16 Jun-03:36:19 Re: the mizunaka collection - quartz (Tobi)
16 Jun-03:34:35 Re: collection of sante celiberti (Tobi)
15 Jun-20:24:31 Re: don lum collection (Don Lum)
15 Jun-17:21:26 Re: collection of sante celiberti (Sante Celiberti)
15 Jun-09:45:28 Re: don lum collection (Don Lum)
15 Jun-06:42:32 Re: collection of volkmar stingl (Volkmar Stingl)
15 Jun-06:18:50 Re: don lum collection (Volkmar Stingl)
15 Jun-00:11:27 Re: unknown mineral from pikes peak pegmatite (Peter Lemkin)
14 Jun-23:53:32 Re: don lum collection (Don Lum)
14 Jun-23:44:16 The mizunaka collection - quartz (Am Mizunaka)
14 Jun-15:48:28 Mineral talks live - episode 39 - dr. Andreas stucki; siber+siber, zurich, switzerland (Bluecapproductions)
14 Jun-15:47:54 Re: collection of sante celiberti (Sante Celiberti)

For lists of newest topics and postings click here


RSS RSS

View unanswered posts

Why and how to register

Index Index
 FAQFAQ RegisterRegister  Log inLog in
 {Forgotten your password?}Forgotten your password?  

Like
83005


The time now is Jun 17, 2021 00:00

Search for a textSearch for a text   

A general guide for using the Forum with some rules and tips
The information provided within this Forum about localities is only given to allow reference to them. Any visit to any of the localities requires you to obtain full permission and relevant information prior to your visit. FMF is strictly against any illicit activities related to collecting minerals.
Canadian Octahedral Pyrites
  
  Index -> Mines and Mineral Localities
Like


View previous topic :: View next topic  
Author Message

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 21, 2009 15:13    Post subject: Canadian Octahedral Pyrites  

One of the most uncommon and impressive pyrite crysals must be the octahedral form. I have seen a few very good examples from Peru and none until now from Canada. I have been working a former pyrite mine in the Province of Ontario with some spectacular results especially in relation to size. I have removed specimens as small as 1/2 cm all the way up to 20 cm. to the best of my knowledge, according to the Royal Ontario Museum, the Smithsonian and other sources, this appears to be possible one of the largest if not the largest octahedral pyrite found. Currently this specimen is on loan to the Royal Ontario Museum.


34.JPG
 Description:
 Viewed:  16059 Time(s)

34.JPG



_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

Peter Megaw
Site Admin



Joined: 13 Jan 2007
Posts: 917
Location: Tucson, Arizona


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 23, 2009 20:58    Post subject: Re: Canadian Octahedral Pyrites  

Al, is there much arsenic around this locality? many of the world's octahedral pyrite localities seem to have abundant enargite and related sulfosalts and I think there is some literature suggesting arsenic "poisoning" is invoilved in octahedral growth development.
_________________
Siempre Adelante!
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 23, 2009 21:20    Post subject: Re: Canadian Octahedral Pyrites  

Peter


I do not have any data that shows an arsenic content in the pyrites. That is not to say there is an absence of arsenic. It does show protochloride of cobalt at .775 cobalt oxide. From any informaton that I can find on octahedral pyrite formation and growth, high temperatures would have to be present. This location would be hydrothermal with a slow cool down allowing for large crystal growth. Crystals in the range of 3 to 4 inches are most common, with 5 to 8 inches and 1 to 3 inches less common.

_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

Peter Megaw
Site Admin



Joined: 13 Jan 2007
Posts: 917
Location: Tucson, Arizona


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 23, 2009 21:41    Post subject: Re: Canadian Octahedral Pyrites  

Al, I'll buy hydrothermal, but large crystal growth is much more a function of low nucleation rate and fast crystal growth than prolonged cooling or other processes.
_________________
Siempre Adelante!
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 23, 2009 22:04    Post subject: Re: Canadian Octahedral Pyrites  

I have been attempting to find the exact reason for the formation of this form of crystals and any attributing factors without much success. One point that seems to come up somewhat consistantly along with temperature is geomagnetic influences at the time. An acquaintance of mine who is a Dr. of Geo-physics was at a loss for an answer.
I have the a map that was produced to show the geomagnetic forces in this area and the mine site is in one of the stronger areas. So, might it be, that both temperature and geo-magnetic forces were at play? It is only a theory.

I do have another thing that occationally happens to batteries when I am in the mine. But that is another story.

_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

alfredo
Site Admin



Joined: 30 Jan 2008
Posts: 853


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 24, 2009 11:11    Post subject: Re: Canadian Octahedral Pyrites  

Peter, Interesting theory about As poisoning and octahedral pyrites. Octahedral and cuboctahedral habits are perhaps the most common in Bolivia's tin and silver veins, being abundant in Llallagua, Colavi, Tazna, Animas... But there's not much arsenic there, and almost no enargite. Almost all the sulphosalts are decidedly Sb-dominant. I wonder whether Sb can have the same effect? Or whether only traces of As will do the trick?
There is an old study on Sb in octahedral galena, but I had the impression that this was more of a temperature-dependent phenomenon, with higher temperatures leading to octahedra and incidentally also allowing more extraneous elements into the structure - I'm not sure whether cause and effect are the right way around here. Pete Richards would probably be able to clarify this. (Incidentally, pyritohedrons are unknown in the tin and silver mines, despite being so common elsewhere.)
Back to top
Reply to topic Reply with quote
Like
   

Peter Megaw
Site Admin



Joined: 13 Jan 2007
Posts: 917
Location: Tucson, Arizona


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 24, 2009 18:57    Post subject: Re: Canadian Octahedral Pyrites  

Alfredo...Sb might do it, I just remember running across the As argument somewhere in the literature. As for octahedral galena-higher temperature link there's a real problem given its abundance in certain Mississippi Valley Deposits which are decidely low T and I think those galenas are pretty clean
_________________
Siempre Adelante!
Back to top
Reply to topic Reply with quote
Like
   

jimB




Joined: 07 Sep 2009
Posts: 51
Location: Tucson, Arizona

View user's profile

Send private message

PostPosted: Nov 24, 2009 22:38    Post subject: Re: Canadian Octahedral Pyrites  

I want a 1 inch floater !
_________________
JimB
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 25, 2009 07:42    Post subject: Re: Canadian Octahedral Pyrites  

JimB

The best that I can do at the moment is a 1.5 inch floater. The majority of what I have are floaters which range up to 8 inches, Let me know about the 1.5 inch. The 8 inch is on loan and is worth bia considerable sum.

_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

Peter




Joined: 16 Jan 2009
Posts: 346
Location: Sweden / Luxembourg

View user's profile

Send private message

PostPosted: Nov 25, 2009 07:43    Post subject: Re: Canadian Octahedral Pyrites  

I think there may be the main component as Alfredo mentioned regarding the temperature influence of the habit. I have not seen the Murgul (Turkey) octahedral pyrite deposit but ther are also other forms present. We have several deposits in Sweden w frozen pyrite octahedrons and there some are Co or As carrying, but I do believe that ir not the reason for the habit. However cubic to more complex pyrites from the Malmberget mine with disturbed curved faces I believe are connected to the inclusions of other elements.

Al, please do find Jim B a killer thumbnail !!! He would really appreciate!
Peter
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 25, 2009 08:54    Post subject: Re: Canadian Octahedral Pyrites  

Peter

I will have a look at my data base and see what I have. I nearly had a big crystal for you but is split in two. It measured about 24cm, so there is still hope, but not until next year.

Al

_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 25, 2009 08:59    Post subject: Re: Canadian Octahedral Pyrites  

Peter asked me to send you a thumbnail of the octahedral pyrite, so here it is.


P3280012_01.JPG
 Description:
 Viewed:  15791 Time(s)

P3280012_01.JPG



P3280004_02.JPG
 Description:
 Viewed:  15776 Time(s)

P3280004_02.JPG



_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 25, 2009 09:16    Post subject: Re: Canadian Octahedral Pyrites  

Peter

One thing that I have found in regards to the crystal growth and influencing factors as to what crystal form will develop, is somewhat ambiguous. It would seem through reading what literature I can find about the growth and crystal forms of pyrite and talking to those experts in the field,is that temperature does play a major part in this. Also as I mentioned before, geo-magnetic influences may also play a role in determining what crystal for will take place. Apparently, the octahedron form indicates a high temperature environment, while cubes are of a lower temperature environment. However, it is less clear as to why they form as they do. So far it is all speculation.

_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

Peter




Joined: 16 Jan 2009
Posts: 346
Location: Sweden / Luxembourg

View user's profile

Send private message

PostPosted: Nov 25, 2009 09:25    Post subject: Re: Canadian Octahedral Pyrites  

Fluorite seem to do the same!
Wish you a great season next year! and hope to see you in Tucson!
Peter
Back to top
Reply to topic Reply with quote
Like
   

David Von Bargen




Joined: 09 Jul 2009
Posts: 41
Location: Milwaukee

View user's profile

Send private message

PostPosted: Nov 25, 2009 09:32    Post subject: Re: Canadian Octahedral Pyrites  

The best book on crystal growth/habist is Kostov and Kostov (1999) Crystal Habits of Minerals which is a distillation of much of the eastern European research on the subject. (the largest pyrite octahedra they record is from Huanzala at 20cm on edge, and 30 to possibly 60cm cubes from Ahchatau, Kazakhstan.) Conditions other than temperature that have been considered also include amount of supersaturation, cooling rate, ratios of iron and sulfur in the hydrothermal solutions, and impurities (As, Sb, Co, Ni).
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 25, 2009 09:40    Post subject: Re: Canadian Octahedral Pyrites  

I will look for that book, but it may be difficult to find. The crystal that I have just got back from being on loan is comparable size wise.
_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   

David Von Bargen




Joined: 09 Jul 2009
Posts: 41
Location: Milwaukee

View user's profile

Send private message

PostPosted: Nov 25, 2009 09:55    Post subject: Re: Canadian Octahedral Pyrites  

Interlibrary loan is probably going to be your friend. It isn't a cheep book and it is fairly technical, so I would go that route first to see if you actually want to shell out the money for it. It is carried in the States by Mineralogical Research Co..
Back to top
Reply to topic Reply with quote
Like
   

prospector




Joined: 21 Nov 2009
Posts: 13
Location: Brockville, Ontario


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Nov 25, 2009 10:15    Post subject: Re: Canadian Octahedral Pyrites  

David Von Bargen wrote:
Interlibrary loan is probably going to be your friend. It isn't a cheep book and it is fairly technical, so I would go that route first to see if you actually want to shell out the money for it. It is carried in the States by Mineralogical Research Co..


David

I'll look into it before doing anything. I once came across a good paper on the subject specifically about octahedral pyrite written by a professor of geology from the university of Alberta lecturing at the University of Hawaii. Unfortunately it was on my old computer which crashed and I lost the paper and haven't been able to find it again on line. It pretty much confirmed what I have been thinking about the formation and influences on the development of this crystal form in pyrite.

Al

_________________
Al Steinburg
Back to top
Reply to topic Reply with quote
Like
   
Display posts from previous:   
   Index -> Mines and Mineral Localities   All times are GMT - 5 Hours
Page 1 of 1
    

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


All pictures, text, design © Forum FMF 2006-2021


Powered by FMF