Mineralman, Riviera or anyone

[JohnD]

At Diamond Hill Sat a speciman was found that was a plate of quartz crystals. On one part of it was a spray
of small cubic crystals about 1/16 to 3/32" on a side. It looked like pyrite, but the mineral was a non-metallic, yellow that was just dull yellow. It looked like it formed as pyrite and was then replaced by another mineral. Any suggestions?

[JohnD]

Rick, Riviera hasn't been to the board for quite a while.
Is he out of town, sick, or still trying to clean all the specimens he got from Diamond Hill?

[Riviera]

Hi John and all I am still here but as Rick said I am get ready for the Spruce Pine show early due to the surgery I am going to have on my shoulder. I will be out of rockhounding for about six months. As for the material at Diamond Hill I have been told that they are Calcites crystal that may have been cast with Quartz. Most of these crystals are hollow. I hope this helps some because I have ask the same question. Riviera ;D

[JohnD]

Got an answer from another person and his was "weathered limonite after pyrite".

[JohnD]

Rick, I've got the dogtooth calcite on several of my specimens. The ones on the specimen I mentioned are actually pyrite crystals where the pyrite has been replaced by another mineral or the pyrite absorbed water and changed to limonite, but retained the original pyrite crystal form.

I've got larger goethite (limonite) crystals, when you break them open you find pyrite inside. The original pyrite crystal is weathering and/or picking up water and changing to goethite and then will go to limonite.