Discussions

💬 Home 🔎 Search 📅 Latest

╳Discussions

💬 Home 🔎 Search 📅 Latest

Groups

Recent Images in Discussions

EducationStrange Malachite formation

30th Dec 2017 18:35 UTCDennis Curtis

I recently acquired a strange Malachite on chrysocolla specimen from the Lupoto mine Katanga DR Congo.

It is 4" wide. I have never seen this type of Malachite formation. Does anyone know the process of how it formed?

Thanks!

30th Dec 2017 18:45 UTCWayne Corwin

Welcome to Mindat Dennis!

What does the underside look like?

Interesting specimen.

30th Dec 2017 19:21 UTCDennis Curtis

It has not arrived yet. Coming in from South Africa. I don't have underside photo.

30th Dec 2017 19:23 UTCDennis Curtis

I found underside pic

2nd Jan 2018 15:25 UTCDennis Curtis

It arrived. Looks just like the photos.

Next time I will wait til I actually have the specimen until posting questions.

Always searching for unique cuprian specimens. Deep Rasberry red Cuprite on dolomite headed my way from the Tsumeb mine. Can't wait to see it!

19th Apr 2018 21:05 UTCGregg Little 🌟

Hi Dennis;

I am coming a little late to this thread to attempt an answer to your question about the malachite on chrysocolla. I hope I am not stating the obvious. The malachite seems to preferentially grow in the boundaries between the chrysocolla botryoidal structures with a greatest growth on the upper most surface; note this might not be the "upper most surface" in the original depositional environment.

This habit seems to point to a preferred nucleation site for malachite crystallization. Much research has gone into this subject and one of the precursors to nucleation is surface topography. The process here appears to start in the boundary areas and then grow outward, almost completely covering a few botryoid tops in the upper portion. This is probably not the only factor working here. Others possibilities are changes in hydrothermal fluid chemistry, activity of chrysocolla crystallization before or during malachite crystallization, etc.

What ever is happening it is a wonderful specimen and a snap shot of crystalliztion processes.

3rd Jun 2018 22:42 UTCDennis Curtis

Thank you Gregg.

Nothing is "obvious" to me concerning crystal formations. I appreciate your comment.

I collect copper minerals and have seen over ten thousand pictures from cyberspace. This one caught my eye.

I can usually see when a specimen is rare but don't know how it got to be that way.

I found a chrysocolla/malachite/cuprite cabochon. The cuprite is vividly dendritic in the chrysocolla. The only one like it have seen.

Thanks again

3rd Jun 2018 22:44 UTCDennis Curtis

This is the cab

Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 24, 2024 05:44:17

Go to top of page