Mineral Hazards

ChrisRockThanks to Chris Tacker, Curator of Geology at the North Carolina Museum of Natural Sciences, for this guest post. 

Museums and cultural institutions frequently get phone calls from prospective donors who want to give away Daddy’s or Granddaddy’s rock collection. Rock and mineral collections can support interesting and educational programs. However, these collections may hold a few surprises that open the institution to a number of unexpected regulatory and/or safety concerns. Radioactivity, radon, asbestos, toxins and carcinogens can all arrive as a part of amateurs’ collections.

To put this in perspective, any rock or mineral is a hazard if it’s moving fast enough. Any rock and mineral above a certain weight is a hazard to your head or feet. With reasonable care, hard hats, and steel toed shoes, these hazards can be minimized.

North Carolina has a remarkable mineral diversity, so there are some North Carolina specialties that turn up frequently in collections. Pegmatites in the Spruce Pine area are known for uranium-bearing minerals that are highly radioactive. Uraninite (pitchblende), torbernite, autinite, clarkeite, or samarskite are all NC minerals that have uranium as one of the principle structural elements. Apatite, monazite, zoisite (especially the pink variety known as thulite) and zircon can carry uranium or thorium as a minor or trace element. There are actually some collectors who specialize in radioactive minerals. Others prize torbernite and autinite because it fluoresces brightly in ultraviolet light.

If enough of these are gathered in one place, the radiation does represent a workplace hazard. These minerals will emit radon, which is a regulatory concern. More than one geologist or collector has possessed a stash of radioactive minerals, then discovered that they can’t sell their house, because the buyer’s radon tests show phenomenal levels of radon. More information on radon is available here.

Asbestos specimen from Polk County, NC

Asbestos specimen from Polk County, NC

Ultramafic rocks are composed of high magnesium, high iron, and low silicon minerals such as olivine and pyroxenes. Ultramafic bodies in the state can produce, and have produced, industrial sized portions of asbestos where the rocks have been metamorphosed. It’s easy to recognize because there are few furry minerals. (You can check out the fuzzy stuff at this site that sells asbestos minerals to collectors) But there are federal regulations on asbestos in all its forms. Problems with regulatory control are minor compared to the problems that museum staff will face if parents learn their child has handled asbestos, even if it is in a ziplock baggie.

You may not think of minerals as fire hazards, but several toxic minerals represent significant fire dangers. Cinnabar (mercury sulfide), orpiment (a very pretty orange or yellow arsenic sulfide, As2S3), and realgar (a very pretty red arsenic sulfide, AsS) emit very toxic gasses in a fire. Steam may make it worse. Firefighters are not prepared for arsenic and mercury gas. Worse, cinnabar and realgar are photosensitive, which means that they break down under visible light. They shed dust as they are displayed, a dust that is quite toxic. If these are in a collection, they need to be stored in a fireproof safe. There is no reason for any of these to be accessible to the public, much less to children.

These minerals double as ingestion/inhalation hazards. For example, realgar is a carcinogen, and is toxic because it contains arsenic. Aresenic accumulates in the human body, as does the mercury from cinnabar. Pretty silver cubes of galena are made of lead sulfide. Lead accumulates in the body, so I recommend that children don’t handle it. A good handwashing will take care of most of the ingestion hazards, but handwashing combined with staying far away from it works even better.

If these are hazardous, why do we keep them in our collection? The Geology Collection at the Museum of Natural Sciences supports education and exhibits, but we are primarily a research collection. We have loaned out asbestos samples from defunct mines to support asbestos research and litigation. Radioactive minerals are extremely valuable for research into isolation of radioactive wastes. What happens to the atomic structure of a mineral or a glass when exposed to long-term radioactivity? Nature has already conducted the experiment. Where else are you going to find a material that has been subjected to radiation for thousands or millions of years?

So be suitably careful and remember: Any mineral moving at high velocity is hazardous.

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This blog will contain posts from the C2C project staff on a variety of topics related to collections care and disaster preparedness. Enjoy the posts and let us know if you would like additional information or have a topic you would like for us to address.

Posted on May 7, 2013, in collections management, disaster preparedness, fire, guest bloggers and tagged , , , . Bookmark the permalink. 6 Comments.

  1. Reblogged this on NC Museum of Natural Sciences Blogs and commented:
    Guest post by Curator of Geology Chris Tacker on NC Connecting to Collections.

  2. Robert van Waasbergen

    Great article. Reminds me of an episode when I was a Geology undergrad, and one of our instructors went into the mineral collection room to demonstrate a Geiger counter. It turned out that the medium-size cardboard box that had been sitting there for as long as anyone could remember was full of radioactive carnotite! Fortunately, I had not spent nearly as much time in that room as I should have.
    Would you suggest geology departments keep an inventory of potentially hazardous minerals in their collections Perhaps even (arrggh, no!) MSDS sheets?

    • Chris Tacker

      Robert! Long time no see.

      It makes sense to keep track of potentially hazardous minerals in a collection. But with any collection, it’s a good idea to have an inventory, even if it’s only a spreadsheet.

      MSDS may not be required. Radiation from naturally occurring sources is not regulated in North Carolina. Other places out west, where the Morrison Formation outcrops, probably have similar regs. What could they do, dig up the entire Morrison for disposal?

  3. What precautions can be taken to prevent any health issues when handling these minerals? I’m currently doing an audit (as part of an internship) of a very large, very old, and somewhat poorly labelled mineral collection, and I’ve come across a few hazardous pieces unexpectedly – asbestos (so far, two pieces of actinolite, one of crysotile, and one labelled only as ‘amphibole asbestos’ – I suspect it’s amosite from the colour), plus a piece of arsenopyrite, and a LOT of galena (much of the collection comes from Broken Hill, Australia, which is best known for lead and silver mining). The more radioactive materials, thankfully, are long gone.

    I’m not handling these pieces a great deal, and I’m wearing gloves, but is there anything else that can be done to prevent any adverse health effects?

    • Chris Tacker

      Well, that’s interesting, Are you in Australia? I’m not familiar with the Australian laws regarding asbestos and asbestos removal. Remember that asbestos hazards are generally for chronic workplace exposure and for smokers.

      When we get a new collection, the first thing we do is go over it with a geiger counter and remove anything that ticks the counter. These are stored in a lead medical cabinet that is used for isotopes, until we can decide on what to do with them. Asbestos and asbestiform minerals get put in a ziplock. We buy 4 mil thickness ones for samples. For God’s sake, keep the labels and the samples together.

      The next issue is dust, from lead minerals or from anything else exotic. It’s good to wear a dust mask. This will also help with personal allergies, for instance, I’m allergic to dust mites and their feces. You can get particulate masks at hardware stores. Gloves are good for handling galena, and it’s also prudent to wash your hands afterwards. Again, lead exposure, like arsenic, is cumulative so the key is being careful now.

      Another real health issue with old collections: back injury. I have back support belts in my lab in every size. I’m forklift qualified, too, something that is not on my resume.

      Handling an old collection like that can be monotonous, but if you’re interested in minerals, it can be an incredible experience. You can get to see things that many geologists don’t get to see in the course of their careers.

      Above all, be prudent and don’t panic. Remember that asbestos minerals and/or galena can’t knock you down and crawl down your throat.

  1. Pingback: Preservation Topic: Hazards in Gem & Mineral Collections | Stuff You Should Know

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