I've been to a few mineral museums like this and one of the interesting ones you can come across is Asbestos. Just hanging out there on display right next to some other mineral. It forms beautiful formations just like the rest, but I've heard so many mesothelioma lawyer commercials that it's easy to forget it's a completely natural material. Also one you can pick apart like cotton and weave into a fabric - it's a flexible material, made out of a rock, which can kill you.

The asbestos formations are ones they keep behind glass.

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bregma 4 hours ago | parent | next [-]

We used to have asbestos rocks sitting around in our house when I was growing up (my mother was born a raised in the town formerly called Asbestos, QC). You could just peel the fibers off the rock. In that form the asbestos is harmless: it's only when it's chopped into shorter fibers and inhaled that it's seriously unhealthy. Industrial uses almost always chopped the fibers so almost no commercial products using asbestos are safe, but the rocks just sitting there are harmless.

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01100011 4 hours ago | parent | prev [-]

Central California has several abandoned asbestos mines which continue to release asbestos into the nearby air and water. I remember considering some hiking around the area once and then came across the warnings regarding exposure.

CA also has a lot of naturally occuring mercury as well. I seem to remember that some lakes in CA are so high in natural(i.e. not from gold mining) mercury that you shouldn't eat the fish.

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throwway120385 2 hours ago | parent | next [-]

The Monte Cristo basin in Washington is high enough in Arsenic that you shouldn't drink water there. There are warning signs at trailheads EG the trailhead leading into Gothic Basin and Gothic Peak.

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nullc an hour ago | parent | prev [-]

There are several different kinds of asbestos and they differ radically in their level of risk and the worst kinds are not (generally?) found in California. So that signage might just be out of an abundance of caution.

I wouldn't be surprised if by the numbers you have a lot more risk of serious injury driving to and from the hike than from the asbestos, particularly if your hiking doesn't involve intentionally disturbing the ground. :)

For the many posters on HN in the bay area-- watch road cuts for green rocks, asbestos co-occurs with serpentinite all over the coast range-- and serpentinite is the state rock! You can easily find some with asbestos, usually grey/white fibrous strands on the rocks. Don't grind it up and huff it, but you can thrill your friends by showing them some boogieman-mineral you found.

(It's only fitting that the state rock is technically known to the state of california to cause cancer... :P)

	▲	bloppe 13 minutes ago \| parent \| next [-]
		> that signage must just be out of an abundance of caution. I'm pretty sure prop 65 applies to all materials known to man, so that checks out
	▲	fragmede 6 minutes ago \| parent \| prev [-]
		Prop 65 requires me to tell you that the device you are reading this on contains chemicals known to the state of California to cause Thinking-regulations-are-stupid-in-test-subjects.