Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on MindatThe Mindat Store
Minerals by PropertiesMinerals by ChemistryRandom MineralSearch by minIDLocalities Near MeSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Ontario Pentlandite

Posted by Lloyd Van Duzen  
Ontario Pentlandite
January 07, 2010 11:08PM
I have confirmed its identity. I thought it was pyrite for quite some time now. Mindat shows a handful of specimens and some are from Sudbury Ontario. In my research I have heard mention of a few occurances here in ontario. So to this point it seems, is it possible that Ontario could be a leader in number of confirmed occurances in the world?

I collected this myself early last fall. Its aproximately 20mmx22mmx5.5mm and is quite dense. 5g per cubic centimeter or something like that.

Just thinking I should research some of the more dense metallic minerals and do a comparison to say Galena, Gold and some of the Copper sulphides.

I didn't check but I wonder if Rock Currier has any other pics of Pentlandite from Ontario?

Here is my Iron Nickel sulphide pics.

Still good to know you guys are out there.

open | download - PICT0002.JPG (867 KB)
open | download - PICT0003.JPG (771.8 KB)
open | download - PICT0009.JPG (933.1 KB)
avatar Re: Ontario Pentlandite
January 07, 2010 11:20PM
These sulfides should be metallic. Your first two photos must be severly oxidised if there are sulfides. Are they magnetic? Pentlandite has a parting and a colour between pyrite and pyrrhotite. Pentlandite and this pyrrhotite are magnetic while pyrite is not. They used to call such ore as in your last photo Norite.
Re: Ontario Pentlandite
January 07, 2010 11:38PM
Well Rob no there seems to be no magnetism.

I thought some Pentlandite was magnetic and some not. It has a greenish black streak, hardness of 3 or 4. and is quite dense. conchoidal as well.

yes I would think it has oxidized, but for some reason I think it looks the same as the day i collected it. Norite seems familiar, I have seen the name recently in my research.

pyrite, chalcopyrite, bornite, and copper have all been sought in the early to mid last century in this area. Even mention of Pentlandite occurances not all that far away.

Whay about crystal habit rob? Have you seen pyrite show this crystal habit?

I think its Pentlandite.
avatar Re: Ontario Pentlandite
January 07, 2010 11:52PM
"greenish black streak, hardness of 3 or 4. and is quite dense. conchoidal as well" sounds like chalco. Pentlandite has a brwnish streak

I don't see any xls. Pentladite is considered a massive mineral, but I did have some ideomorphic xls frozen in chalco from thr Monshe Tundra.
Re: Ontario Pentlandite
January 08, 2010 01:22AM
I took your suggestion about the toilet tank streak plate and it seemed to leave a dark greenish black streak, possibly to a brownish black.

Chalco is a very good possibilty I believe I have a sample. There is a slight difference in color, chalc is more dully brass yellow and Pentlandite is more brighter yellow. And one would think that oxide can change the surface color in copper sulphides. Pyrites show a silvery color on fresh fractures and when oxidation occurs it changes to that dull brassy yellow. I have witnessed this before. chalcopyrite tends to have the brassy yellow because of the iron content then can change to the irridescent colors more associated with it through oxidization. In the samples I have, there is no signs of the irredescent colors, just the metallic brassy yellow. But differ in crystal habit, fracture and color.

Trying not to place to much focus on color, so the other tests come in to play.

You got some good points about the chalcopyrite. I am trying to rule out other pyrite's because of the crystal habit, hardness and fracture.

Thought I was making a confident, educated guess. That identity comfirmation sure is hard to get a hold of.

And Rob I know your a well educated guy with lots of history and experience so your word is important to me.

I have been busy on the geological prospective the last couple months, planning prospects for minerals I seek.

I did get The National Audubon Society Feild Guide to Rocks and Minerals, right full of Rock Currier's pics for christmas and it gave me the first clue about the Pentlandite. So thats a confidence builder for me. It had me confident enough to come and post it on Mindat.

Guys like you and rock bring alot to the table when the mysterious world of minerals has alot of us guessing.

Thanks again Rob.
avatar Re: Ontario Pentlandite
January 08, 2010 01:48AM
Thanks for the kind words. Pentlandite on a fresh surface is a brown yellow, more brown than a fresh chalco surface. You are quite right about oxidation and tarnishes. Check the streak of your known chalco with this one. The joy of the resevoir top is that you have room for a lifetime of streaks and they store very well.
avatar Re: Ontario Pentlandite
January 08, 2010 01:00PM
North Rock,

I haven't gotten to uploading any images of P minerals, but I checked and I have no Images of Pentlandite to upload. Sorry.

Rock Currier
Crystals not pistols.
avatar Re: Ontario Pentlandite
January 08, 2010 04:11PM
I have a sample of pentlandite I can take a picture of and upload. Will do so this weekend.
avatar Re: Ontario Pentlandite
January 08, 2010 04:21PM
In my limited experience, pentlandite is intimately associated with pyrrhotite (although I understand that it can be granular). The only way I have been able to differentiate the pentlandite from the pyrrhotite is by reflectance from polished chips.
avatar Re: Ontario Pentlandite
January 08, 2010 07:34PM
Don, that's the Norite. Lumps of pretty pure pentlandite do exist, but Norite is the common ore.
avatar Re: Ontario Pentlandite
January 08, 2010 07:39PM
is Pyrrhotite/Nickeloan Pyrrhotite's streak as brown/bronzy as Pentlandite? Not exactly conclusive mind you, but on a confirmed massive specimen from Sudbury I believe I've been able to observe areas, using porcelain tipped probes, that had different streak coloration, i.e. seemed discernible.

I've actually been searching in this way through many samples of Nickeloan Pyrrhotite from the Gap Mine, for evidence (i.e. a specimen) of the elusive (possibly erroneously reported) Pentlandite from this deposit. Unfortunately I've had no success thus far (no real discernible color variation/streak). I do need a very easy and inexpensive initial test to warrant any additional analysis, so I would like to know from you and others with experience, if you believe my assumption of what I thought I observed on the Sudbury piece to be simply a faulty assumption.

Mine is a "needle in a haystack" kind of situation, so I don't want to waste a great deal more effort with this method if you think it unlikely to yield the desired result. BTW, I surely appreciate this string and any input here from others as well. thanks much!


Edited 1 time(s). Last edit at 01/08/2010 07:42PM by Mark Heintzelman.
avatar Re: Ontario Pentlandite
January 08, 2010 07:42PM
Ther must be a simple chenical test for Ni. Back to fusibility and blowpipes?
avatar Re: Ontario Pentlandite
January 08, 2010 08:10PM
The only thing that you can confuse pentlandite with in the Sudbury ore is pyrrhotite. However the pentlandite has a distinctive parting that is always present in the larger grains and a slightly darker color. Once you recognize it, it is relatively easy to identify. I will upload a picture later that shows the difference.
Re: Ontario Pentlandite
January 08, 2010 10:37PM
A simple chemical test for Ni. Use Dimethylglyoxime if you can find it. Once used by prospectors to show the presence of Ni. It's probably more common now to have assays done.

"If it can't be grown it's gotta be mined. "
avatar Re: Ontario Pentlandite
January 08, 2010 11:20PM
Thanks Reiner, that is what I also remember now that you have jogged my memory.
avatar Re: Ontario Pentlandite
January 09, 2010 04:10PM
The color of the streak should differentiate the two minerals. But, I think that if the two are mixed, interpretation might be a problem.

Dimethyl glyoxime is a very sensitive test for nickel, and one easy to do; but; the iron should be removed first. Dissolve a grain of mineral in HNO3, neutralize and make slightly basic with NH4OH, and add a drop or two of dmg solution. A red lake indicates Ni. The OH- will precipitate a brownish red Fe(OH)3 that should be filtered out before adding dmg to the solution. The test can also be done on a microscope slide sized plate of quartz (not polished) streak plate. A 1 cm streak is sufficient. Add drops of chemicals onto the streak. Heat the plate gently in an alcohol flame and agitate with a glass stirring rod to dissolve the streak. I believe you can obtain the chemicals from (Florida).

A cold borax bead from the oxidizing flame that is red or brown in color indicates Ni ( hot red could be Fe). A cold sodium ammonium acid phosphate bead from the oxidizing flame for Ni is yellow or orange.
avatar Re: Ontario Pentlandite
January 09, 2010 04:38PM
I don't see any significant macroscopic pentlandite on these specimens to talk about it.:) Even if it present here in some quontity, it don't deserve some kind word as material for collection.
I am think, that it is possible to find much more valuable pentlandites on the deposit.;)
avatar Re: Ontario Pentlandite
January 09, 2010 04:54PM
I didn't see it there Donald, but this place has it.
avatar Re: Ontario Pentlandite
January 09, 2010 05:35PM
Attached are two pictures of Pentlandite from the McCreedy West mine, in Sudbury, Ontario. The first shows the parting, the second the difference in color between chalcopyrite and the pentlandite. Unfortunately I do not have a sample of pentlandite in pyrrhotite to show you because the contrast between the two is poor, I never had a desire to acquire one. If you want to see more including micro pictures, I have posted more photos to the database but they are waiting approval at the moment.

Edited 1 time(s). Last edit at 01/09/2010 05:39PM by Reiner Mielke.
open | download - Pentlandite Parting.JPG (246.5 KB)
open | download - Pentlandite,Cpy,Millerite.JPG (246.3 KB)
avatar Re: Ontario Pentlandite
January 09, 2010 06:31PM
Nicely illustrated Reiner...


  • Valid attachments: jpg, jpeg, gif, png, pdf
  • No file can be larger than 1000 KB
  • 3 more file(s) can be attached to this message

Spam prevention:
Please, enter the code that you see below in the input field. This is for blocking bots that try to post this form automatically. If the code is hard to read, then just try to guess it right. If you enter the wrong code, a new image is created and you get another chance to enter it right.

Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2015, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: December 1, 2015 18:32:06