Topic: Marcasite or Pyrite in Graveyard Point Plume (Read 774 times)

55fossil · « **on:** December 10, 2018, 09:14:08 AM »

Without a microscope to view the structure I have no idea how to distinguish between marcasite and pyrite in agate. Seeing as this makes a roostercomb like cloud I think it is marcasite. But I also see what appear to be golden pyrite cubes. Possibly both, I have no idea. Here are two images to ponder. Please help identify.

yukonjade · « **Reply #1 on:** December 10, 2018, 10:50:15 AM »

Marcasite has the same chemical formula as pyrite but has a different structure.

gemfeller · « **Reply #2 on:** December 10, 2018, 12:15:29 PM »

One way to differentiate them according to my old mineralogy textbook is to soak a specimen in a strong nitric acid solution. Pyrite gives no reaction but marcasite gives off excess sulfur, leaving the solution cloudy. In a dilute nitric acid solution some bubbles may be observed.

Redrummd · « **Reply #3 on:** December 12, 2018, 09:30:09 PM »

Looks like mostly marcasite with a bit of pyrite mixed in.....

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Author Topic: Marcasite or Pyrite in Graveyard Point Plume (Read 774 times)

55fossil

Marcasite or Pyrite in Graveyard Point Plume

yukonjade

Re: Marcasite or Pyrite in Graveyard Point Plume

gemfeller

Re: Marcasite or Pyrite in Graveyard Point Plume

Redrummd

Re: Marcasite or Pyrite in Graveyard Point Plume