FMF - Friends of Minerals Forum, discussion and message board

[John Williams]

Hi Guys
I thought I'd share this monster specimen with you.
I have collected at the above site several times but on one occasion early this year I prized out this monster! It measures 42 cm x 33 cm and must weigh at least 20 kilos.
It is liberally sprinkled with gorgeous small gemmy crystals and clusters of erythrite.
I carried it about 500 metres to get it to my car and nearly gave myself another hernia. I had an operation for a hernia 3 years previously!
I have a question for the forum. Am I correct in thinking that areas of white crystallised/powdery mineralisation is pharmacolite? [Which I believe is toxic!?].
So I survived not getting a hernia or poisoning myself- the specimen was cetainly worth the risk!
All comments welcome.
Regards
John

[Tracy]

mindat says that pharmacolite gets its name from the Greek word for "poison," in allusion to the fact that it contains arsenic. But I can't find any tox reference stating that it is toxic - just because it has arsenic in it wouldn't make it so...?

- Tracy

[John Williams]

Thanks Tracy
John

[Calita]

Don't worry at all .It's not farmacolite. It's aragonite.Sure. Regards.

[str4hler]

Hi John, I was there a few times to collect, and I dare to say that 90% of the white stuff is aragonite. Cheers! Frank

[John Williams]

Cheers Calita
Happy Xmas
John

[John Williams]

Cheers Frank
Happy Xmas

[Calita]

Happy merry Xmas for you and all the forum.Regards.

[alfredo]

Tracy, Pharmacolite is slightly soluble in water, so maybe that's why it is/was considered one of the more poisonous arsenates?

[Tracy]

Possibly, but as an entity it's not listed in any of my references. Water solubility would not be a huge factor unless except in situations involving ingestion or inhalation exposures. To me, "slightly soluble" in water doesn't suggest a high degree of hazard, except maybe if one were mining the stuff (and inhaling lots of dust) or living in a tropical environment surrounded by pharmacolite (inhaling water droplets with dissolved arsenic in them).

EPA estimates a safe level for chronic oral exposure to arsenic at about 2 ug/day in drinking water, and toxic doses are in mg range. And I don't imagine getting mg-range doses of arsenic from one arsenic-bearing specimen, even a large one. All this being said, I allow for the possibility of error - note that my original posting ended with a question mark. :-)

- Tracy

[John Williams]

Many thanks Tracy for the research you have done on pharmacolite. I was a little concerned that dust from extracting specimens might be a hazard but it seems this is quite low. In fact a number of other contributors to this post suggest that the mineral in question at this site is aragonite!
Regards
John