Post by 150FromFundy on Mar 8, 2014 15:46:23 GMT -5
I’ve been going through old boxes of rocks collected on past vacations in hopes of finding an overlooked display specimen. This one is border line on whether it deserves shelf space, or not. It’s one of those rocks that may be a little more interesting than beautiful.
Serpentine – This is a piece of serpentine from the Advocate Mine on the Baie Verte Peninsula in Newfoundland. The mine was opened in 1955 and closed in 1981. The mine produced asbestos fiber. In the 1970’s, health impacts amongst the workers were being noticed. A latter study found that 10% of the workers were suffering asbestos related illnesses. The mine currently remains closed due to health concerns creating a limited market for asbestos fiber.
Serpentine is a tough mineral to figure out. It is often found along contact zones resulting from contact metamorphism. The variation in heat and pressure is probably responsible for the varieties of serpentine.
The host rock is easier. It is Peridotite which is a combination of Olivine and Pyroxene. Both Olivine and Pyroxene are iron and magnesium rich silicates, so the rock is heavy.
Top Side – Picrolite (I think)
Picrolite is a non-flexible, fibrous variety of serpentine.
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Top Side Zoom – Picrolite (I think)
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Bottom Side - Altered Chrysotile (maybe)
The bottom side appears to be fibrous Chrysotile asbestos. At least that’s what I was aiming for when I collected it.
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Bottom Side Zoom – Altered Chrysotile (maybe)
Upon closer examination, what looks like fibrous Chrysotile asbestos is actually quite hard and impossible to scratch deadly fibers off of.
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Bottom Side Zoom – Altered Chrysotile (maybe)
Even closer, it appears semi-translucent and quite glassy.
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Darryl.
Serpentine – This is a piece of serpentine from the Advocate Mine on the Baie Verte Peninsula in Newfoundland. The mine was opened in 1955 and closed in 1981. The mine produced asbestos fiber. In the 1970’s, health impacts amongst the workers were being noticed. A latter study found that 10% of the workers were suffering asbestos related illnesses. The mine currently remains closed due to health concerns creating a limited market for asbestos fiber.
Serpentine is a tough mineral to figure out. It is often found along contact zones resulting from contact metamorphism. The variation in heat and pressure is probably responsible for the varieties of serpentine.
The host rock is easier. It is Peridotite which is a combination of Olivine and Pyroxene. Both Olivine and Pyroxene are iron and magnesium rich silicates, so the rock is heavy.
Top Side – Picrolite (I think)
Picrolite is a non-flexible, fibrous variety of serpentine.
[/URL]
Top Side Zoom – Picrolite (I think)
[/URL]
Bottom Side - Altered Chrysotile (maybe)
The bottom side appears to be fibrous Chrysotile asbestos. At least that’s what I was aiming for when I collected it.
[/URL]
Bottom Side Zoom – Altered Chrysotile (maybe)
Upon closer examination, what looks like fibrous Chrysotile asbestos is actually quite hard and impossible to scratch deadly fibers off of.
[/URL]
Bottom Side Zoom – Altered Chrysotile (maybe)
Even closer, it appears semi-translucent and quite glassy.
[/URL]
Darryl.