Tuesday, May 20, 2014

Geo 730: May 20, Day 506: Lawsonite?

I'm really not sure what this pocket of minerals actually is, but lawsonite seems a reasonable guess. It's fairly common at Bandon's blueschist jetty, and should be easy to find for other visitors- probably not this same block, but there are plenty of similar samples. In reading over the wikipedia entry on lawsonite, the thing that jumped out at me- which I had either not known or had forgotten- was how hard that mineral is: 7.5-8 on the Mohs scale. This gives an easy, if not necessarily diagnostic, field test if you have or can find a bit of quartz lying around. A fragment of lawsonite would be able to scratch quartz, and there are relatively few minerals for which that's true. I need to remember that the next time I visit Bandon!

Photo unmodified. March 9, 2012. FlashEarth location.

No comments: