FMF - Friends of Minerals Forum, discussion and message board

[elgreba]

Hello! Have a question about mineralization in granite. I have found granite boulders containing arsenopyrite and malachite .. It is worth putting effort into/granite? Possible to gold or other precious metals accumulated in the sulfides/granite? What I can see it goes small quartz veins through the granite, where the sulfides are collected. Any help would be great!
Sincerely Andreas

[GneissWare]

Elements that are incompatible in a silicate melt tend to concentrate in the late stage fluids resulting in deposition as fracture filling and constituents of quartz veins and pegmatites. So, if your question is -- Is it possible? then the answer is yes. As to if it is likely or probable, an assay would tell.

[Peter Megaw]

This sounds a lot like porphyry copper style mineralization...where fractures and micro-fractures in the crystallized granite host sulfide deposition in quartz veinlets. Google "porphyry copper" and you should get a full primer. Are these in place or are they transported boulders in a stream? Could have exploration significance

[elgreba]

Hey.

Thank´s for the quick answer! I will prospect the area further. Im finding rough edged boulders near a rock formation up high in the terrain, which indicate that they dosen´t transported far. I could put up a picture and more when ivé been there again looking at those formations. Thank´s!

Best regards Andreas

[Riccardo Modanesi]

Hi to everybody!
Non-silicate minerals aren't seldom at all to be found in granite rocks!
Let's think about fluorite, for example! Last year I found (and not only myself!) some beautiful crystals in the Strzegom granite quarries (Tomek does remember it for sure!), and fluorite does not contain even a nanogram of silicium!
Greetings from Italy by Riccardo.