FMF - Friends of Minerals Forum, discussion and message board

[straycat6]

is anyone familiar with this mineral?, outside is green and mostly brown and inside has sparkling green crystals

Thank you for your time

[Bob Harman]

It would help to know where it is from. It looks like druzy quartz atop malachite.

Wherever the malachite lined an open cavity, it allowed a thin layer of druzy quartz crystal tips to form.

[straycat6]

[straycat6]

here is a picture of the bottom

[Peter Megaw]

There is very similar material from Concepcion del Oro in Mexico and probably at least one Arizona locality. You might try browsing the pictures of malachite + quartz on mindat for Concepcion, Bisbee and Inspiration and see if something matches

[straycat6]

Will do, thanks

[Volkmar Stingl]

Why are you all so sure, that this is quartz on malachite? Why not calcite? There is no detailed picture of the druzy cover, no hardness test, no acid test!

Volkmar

[Bob Harman]

Volkmar, When you see a cat that looks like a cat, you don't have to waste your time doing genetic testing to make sure it is not a dog or bunny rabbit.

When you see quartz over malachite and it almost certainly comes from one of several localities in Mexico or Arizona, you don't have to spend time doing any testing, especially after Peter Megaw, a recognized Mexican mineral expert agreed.

Mexican expert P Megaw even posted a reference picture showing a very similar looking example of quartz over malachite from a known locality. If you, Volkmar from Austria, wish to challenge the mineral identity, your response would be seriously helped by your including a reference picture showing an example what you think the mineral could also be. Bob

[Bergur_E_Sigurdarson]

Bob.... your response to Volkmar sounds very aggressive... whether that was intended or not.

I tend to agree with Volkmar, that using scientific metods to establish what a mineral is and teaching how to (using acid for bubble test in case of calcite versus quartz as suggested) is a lot more helpful than a "blind" belief in an experts suggestion, that only takes into account a rather blurry photo from the original poster, where I at least fail to be able to tell 100% what the minerals are as I can't see their structure and shape clearly enough to do so.

Yes, I also agree that the suggestion of such an expert as Peter Megaw is extremely likely to be correct, and would tend to take his word on it. But, his is a suggestion, and while the sample image he provided is very nice, it is not very similar in my eyes to the one of the original poster.

Volkmar didn't even firmly suggest it wasn't quartz or calcite... adding a questionmark .... I understood his reply simply as one that should encourage the original poster to do whatever tests they could to establish that the suggestions that others provided were correct.
Should we not encourage people to learn how to identify instead of just taking first suggestion (even if it comes from an expert) ?