Lapidaryforum.net

Please login or register.

Login with username, password and session length
Advanced search  

News:

Welcome new members & old from the Lapidary/Gemstone Community Forum. Please join up. You will be approved after spam check & you must manually activate your acct with the link in your email

Congratulations to Sandsave and his Crinoid Cab!

 www.lapidaryforum.net

Another cabochon contest coming soon!

Pages: [1]   Go Down

Author Topic: Reasonably certain it's pyrite  (Read 314 times)

0 Members and 1 Guest are viewing this topic.

Kaljaia

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 647
Reasonably certain it's pyrite
« on: May 03, 2019, 10:14:57 PM »

First time hitting a metallic inclusion. It turned the oil black and smelled like a swamp, so I'm gonna guess pyrite!
In common opal I think, haven't done a hardness test but it cut too soft and smoothly to be a hard agate.

Logged


- Erika

I rock hunt in the Antelope/Ashwood area of the John Day river basin in Oregon. 90% of what I post is from this area, from private property where I have permission to hike and collect. The material I find is for personal use only, I do not have landowner permission to sell. Thanks for understanding!

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2621
Re: Reasonably certain it's pyrite
« Reply #1 on: May 04, 2019, 07:58:41 AM »

Don't forget about marcasite.
Logged

Slabbercabber

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 366
Re: Reasonably certain it's pyrite
« Reply #2 on: May 04, 2019, 10:24:30 AM »

Psilomelane would be my guess.  Black oil being the clue.
Logged

Kaljaia

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 647
Re: Reasonably certain it's pyrite
« Reply #3 on: May 04, 2019, 06:31:53 PM »

Psilomelane would be my guess.  Black oil being the clue.

Would manganese have the sulfur smell and rust oxidation tho?
Logged
- Erika

I rock hunt in the Antelope/Ashwood area of the John Day river basin in Oregon. 90% of what I post is from this area, from private property where I have permission to hike and collect. The material I find is for personal use only, I do not have landowner permission to sell. Thanks for understanding!

Slabbercabber

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 366
Re: Reasonably certain it's pyrite
« Reply #4 on: May 05, 2019, 06:12:46 AM »

I can't answer the smell question as my nose has never been worth much.  Marcasite and pyrite will oxidize but that is not the same as rust.  If you have actual rust then there must be raw iron.  That seems a bit unlikely.
Logged

rocks2dust

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 371
    • rocks2dust items on ebid.net
Re: Reasonably certain it's pyrite
« Reply #5 on: May 05, 2019, 07:45:13 AM »

Would manganese have the sulfur smell and rust oxidation tho?
No. Psilomelane isn't a sulfide. Pyrite (streak is dark brown) and marcasite (streak is black) both give off the sulfurous smell.
Logged
r2d

surplus odds and ends that I have on ebid.net
· Xtra gemstones
· Xcess fossils, minerals and rough
· Everything else

irockhound

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 833
    • RockhoundingUSA
Re: Reasonably certain it's pyrite
« Reply #6 on: May 05, 2019, 10:41:34 AM »

I have cut a lot of Nipomo Marcasite agate and it always has that odor and will also turn the water black.
Logged

Kaljaia

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 647
Re: Reasonably certain it's pyrite
« Reply #7 on: May 05, 2019, 07:58:31 PM »

I have cut a lot of Nipomo Marcasite agate and it always has that odor and will also turn the water black.

Yeah, I figure it's at least FeS2, either Marcasite or Pyrite. The individual crystals look more squared off than the organic forms in Marcasite images, but it's hard to tell. The "Rust" I was referring to is the orange powder and pitting on stone in places. It looks like any metallic surface exposed to air has deteriorated. There was no surface indication of metallic inclusions, only some pitting and orange residue. I'm putting together a little local material "sampler" for ID fun. Do you think "iron pyrite" would be an appropriate label?

Cut another stone tonight with metallic flecks, picked up a few miles away! Apparently it is now the season for metallic inclusions.
Logged
- Erika

I rock hunt in the Antelope/Ashwood area of the John Day river basin in Oregon. 90% of what I post is from this area, from private property where I have permission to hike and collect. The material I find is for personal use only, I do not have landowner permission to sell. Thanks for understanding!

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2621
Re: Reasonably certain it's pyrite
« Reply #8 on: May 05, 2019, 09:17:56 PM »

The orange powder sounds like decomposed pyrite not marcasite.
Logged

irockhound

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 833
    • RockhoundingUSA
Re: Reasonably certain it's pyrite
« Reply #9 on: May 05, 2019, 10:57:12 PM »

I would go with the Iron Pyrite label.  Lithic is right with the powder and Marcasite (at least the ones I have collected) when they go bad they tend to go gray to whitish powder.
Logged

Kaljaia

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 647
Re: Reasonably certain it's pyrite
« Reply #10 on: May 05, 2019, 11:19:27 PM »

Ok, I'll go with that! Thanks for help on the ID!
Logged
- Erika

I rock hunt in the Antelope/Ashwood area of the John Day river basin in Oregon. 90% of what I post is from this area, from private property where I have permission to hike and collect. The material I find is for personal use only, I do not have landowner permission to sell. Thanks for understanding!

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2621
Re: Reasonably certain it's pyrite
« Reply #11 on: May 06, 2019, 06:12:49 AM »

Limonite is the breakdown product of pyrite  and not much fun when you think you have found pyrite cubes but get a closer look and see they are falling apart limonite.
Logged
Pages: [1]   Go Up
 

Page created in 0.115 seconds with 49 queries.