FMF - Friends of Minerals Forum, discussion and message board

[Godscreation1988]

You are correct Herwig; I just don't have it in me to test the mineral Specimen with chemical means. The substance is likely toxic and could create fumes (?) and I do not have a fume hood.

My current consensus is an identification of scoria and Mimetite (and of course a little organic matter from the collection site),otherwise known as lead chloroarsenate, based on a number of photos and the descriptions of the mineral online.

Pyromorphite is another contender.

I might get out my blacklight and laser pointer and see how light looks through it.

Thank you again everyone for your thoughts and suggestions and for welcoming me onto the forum.

[Kevin Schofield]

[Godscreation1988]

Thank you for your insightful response Kevin. I agree. I could get a cheap Mohs hardness scale testing kit and also try an acid (vinegar). One of these days I will do that but for now I will just keep the specimen intact. Next time I go to the local big box store I will check and find out where the lava rock comes from if I can to narrow down the possible origin of the specimen.

Thank you again everyone.

Michael

[Godscreation1988]

Follow-up post, for anybody interested...My (possible) mimetite illuminates (possibly glows too) under a blacklight. Mimetite is lead arsenate chloride.

[Godscreation1988]

Another photo under the blacklight...

[Forrestblyth]

From just a visual indication I would tend to agree with Herwig that the most likely candidate would be aragonite.

It's very difficult to ID things visually as variation can often look completely different at many locations visually.

I do applaud you on self-collecting and encourage you to continue to do so. It is so much more rewarding to acquire your specimens in the field.

If the only means you have to ID is visual, try visiting a local museum that has actual specimens to see or compare to known specimens in the hand.

Obviously following to set chemical means as described is a fantastic skill to learn and something to aim for in the future.

But in the meantime keep collecting and posting and share please. i enjoyed seeing what you found and share your passion for the hunt.

I will post a picture of a known specimen to compare.

[Forrestblyth]

To emphasise how completely different specimens look visually look at this Aragonite From Morocco

[Godscreation1988]

Forrest,

Thank you for your thoughtful and insightful replies.

The mineralogy profile of aragonite matches the mineral formation on my red scoria specimen. I am content with a tentative identification of aragonite or mimetite (without chemically testing a potentially toxic compound(s), as I am planning on keeping this piece until I donate it when I pass.

The next time I am visiting a major city I will look into exploring a local museum. Indeed, I may purchase a Mohs testing device and a chemical kit to test any inert mineral specimens I have. I love exploring the wild, looking for unusual rocks, minerals and gems; even if this just means looking around my humble yard/garden. Sometimes, I stumble across something interesting enough to hang on to.

Best to you and yours Forrest!

-Michael

[Godscreation1988]

Also Forrest, I agree that the varying mineralogical morphology of the specimens is often accounted for by the differing geographical origins of the specimens of a single mineral species in question.

Mimetite and aragonite (as you pointed out), for example, often display tremendous morphological (and likely others, such as chemical) differences depending on where a particular species is found. I have also observed differences in ruby corundum from North Carolina and Asia respectively. This makes sense, since the formation parameters are so variable depending on where in the earth the specimen in question is formed and on the chemical and other processes and forces that affect the specimen up until and after it surfaces.

As I am just beginning to learn a bit about the disciplines of petrology, mineralogy and gemology, forgive my lack of technical knowledge and insight.

-Michael