I have a very odd piece of pyrite that appears to be littered with microscopic spheres. I have read a host of articles about pyrite but can't seem to find anything that can even began to explain how or why this happened. Some of the crystals have spheres embedded halfway in them and I've crushed a few crystals and found spheres inside them. Has anyone every come across anything like this? 

The spheres are called “framboids” and here is an extensive article speculating about their possible origins. Large framboids are collections of smaller framboids rather than true crystals.

 https://www.researchgate.net/publication/313528873_Framboids_From_their_origin_to_application

Edited April 30, 20223 yr by bangstrom
The original citation didn't work

2 hours ago, bangstrom said:

The spheres are called “framboids” and here is an extensive article speculating about their possible origins. Large framboids are collections of smaller framboids rather than true crystals.

 https://www.researchgate.net/publication/313528873_Framboids_From_their_origin_to_application

Interesting - something I did not know about.

However from what I read, framboids are said to be composed of microscopic, even sub-micron, euhedral crystals, so they are crystalline, apparently. It seems that their formation is hypothesised to occur when pyrites form from organic matter, via greigite, Fe3S4.

13 hours ago, Kurious12 said:

I have a very odd piece of pyrite that appears to be littered with microscopic spheres.

Interesting topic and photos. +1

4 hours ago, bangstrom said:

The spheres are called “framboids”

Thanks for the article. +1

Yeah, thanks for the article, this helps a lot.

On 4/29/2022 at 10:12 PM, bangstrom said:

The spheres are called “framboids” and here is an extensive article speculating about their possible origins. Large framboids are collections of smaller framboids rather than true crystals

I had an edx analysis done on one of these framboids a while back and these appear to be made mostly of carbon. I have come across a lot of other strange microscopic structures in this pyrite, some look metallic, but all appears to be made mostly of carbon so, I can't help but wonder if all of this stuff is somehow related.

1 hour ago, Kurious12 said:

I had an edx analysis done on one of these framboids a while back and these appear to be made mostly of carbon. I have come across a lot of other strange microscopic structures in this pyrite, some look metallic, but all appears to be made mostly of carbon so, I can't help but wonder if all of this stuff is somehow related.

That might fit with what I was saying about an organic origin for the pyrite. 

Perhaps the organic parts come from decayed fossils from this process

http://preparation.paleo.amnh.org/56/pyrite-disease

https://www.zoicpalaeotech.co.uk/pages/pyritefossils

5 hours ago, studiot said:

Perhaps the organic parts come from decayed fossils from this process

This is something that I can't confirm nor deny. I do find this to be very interesting because there were two tiny fossils found inside of this pyrite, but scientist could not explain the state of preservation they were in, one I was told dates back to 200 million years and the other could not be identified at all. Thanks for the articles, I will indeed read those again.