Realgar - Orpiment - ARSENIC

The red Realgar will turn into yellow/brown Pararealgar with exposure to light. I am not sure if the clear plastic will remove enough UV to stop that process.

So Vince, are you saying Bumblebee also contains arsenic? I had not heard that before. I’ve slabbed it but never cut cabs from it. Definitely handled it both wet and dry.
Jeff A

Yes, you can.  Copper based rocks should always be cut wet and it's recommended that you wear a respirator or at least a mask.  Some of us do, some of us don't.  I will usually (not always) wear an N95 mask when I'm cutting copper stuff, but there are lots of people who don't.  Lots of water probably keeps most of the bad stuff from becoming airborne.

This may be helpful to some people:

www.gemsociety.org/article/gemstone-toxicity-table/

Take it with a grain of salt, though, since some things that are chemically identical are listed with different toxicities.

Generally speaking, as I’ve said before, keeping material wet, and working with adequate ventilation will protect you. For most people, masks will be a false sense of security, since they are typically worn incorrectly.

For Some materials, as mentioned above (lead, arsenic, some copper materials), additional precautions may not be a bad idea.

That said, I remember one day at the club, when an old-timer licked a rock and commented, “yup, that has arsenic. It tastes like garlic.”

I believe he’s still around.

For many compounds you can look up the toxicity by their Safety Data Sheets (SDSs).

For malachite (copper carbonate, basic), the oral ld50 is 1.35g/kg, meaning a 75kg person would have to ingest about 3 ounces. It is listed as a respiratory irritant, not a danger. People with respiratory conditions, such as asthma, should exercise caution. Those same people should also exercise caution in wearing a respirator, as they restrict breathing.
Orpiment (arsenic sulfide), on the other hand, has danger as the signal word, and is immediately gangrenous to life and health (IDLH) at a concentration of 5mg per cubic meter

Also remember that just the metal does not make the poison. The counter ion plays a role as well, so not all copper minerals have the same toxicity. You have to figure each one out individually.

Finally, ALL dry rock dust poses a physical hazard, due to microscopic sharp edges that can damage lung tissue. This is mostly, independent of chemical formula. Only to the degree that formula determines crystal structure, does it play a role in this regard.

Re: Congo Malachite. I used to cut a lot of it. A relative worked in the Congo as a helicopter pilot ferrying rough diamonds from DeBeers mines to the capital. He sent me a lot of fine malachite rough in the form of ashtrays, legal to export, and I went on a cutting spree. I used lots of water while cutting.

I can't recall how long it took or how much I cut before I noticed a strong metallic copper taste in my mouth. I didn't use any protective gear. I had the good sense to quit cutting it so frequently, though I've cut occasional cabs since with no ill effect.

Someone once told me the copper enters the body through the skin as well as the nose and mouth. I don't know if that's true or not but it's definitely a material to be careful with. I often think of the Congolese laborers who cut decorative pieces from it without water or protection for years on end. I doubt they have long lifespans.