FMF - Friends of Minerals Forum, discussion and message board

[Roger Warin]

Hello,
I had the chance to observe under my binocular this beautiful sample of calaverite from Creeple Creek, Colorado.
I have 3 questions :
1) Secondary mineral = fluorite?
2) Calaverite is sometimes covered with fluorite, like in lasagna?
3) is there a beginning of alteration in gold?

Thank you.

[Bob Carnein]

Your calaverite appears to be coated with chalcedony, which is pretty common at Cripple Creek/Victor. For me, the photo isn't clear enough to show alteration to gold.

[Roger Warin]

Thank you very much for your relevant response.
I replaced the specimen under the lens and here are two photos.
1) 8X magnification
2) 100 X.
Without translation between images. The crystal is in the center.

With magnification, some faces lose their original colors.
Light plays a big role.
I am using ring lighting with annular LED illuminators.