SG--crystals, gems -- Obsidian

catlin said:

Thanks hermit, should I ever become a millionnaire I will keep that in mind.

B/W we also have some extinct volcanoes here, in the Eifel, maybe I should go there next year on a holiday?

Click to expand...

May or may not do you any good catlin.

Unless your volcanoes are relatively young and had extensive lava flows or large "ejections" you won't find any obsidian. That's why i suggested Hawaii.
Even then, not all flows produce obsidian.

Many Hawaiian flows simply produce what is know as "tuft" or pumice.
You need the right type of lava and extremely quick cooling to get our favorite natural glass.

There is almost no obsidian found in the eastern u.s. as all of the mountains are so old that volcanoes and their flows have long ago eroded way.

California and the rest of the west has large obsidian deposits because our mountains and volcanoes are very young geologically speaking and many of the volcanoes had massive lava flows. Part of southeastern Oregon, northeastern California and Idaho are covered by one massive flow. And let us not forget the Cascade mountains of Washington, Oregon and California where there are 6 significant volcanic mountains that are still considered active. In Washington—Mt. Adams, Mt. Baker, Mt. Rainier and Mt. St. Helens which had a massive pyroclastic eruption on May 18, 1980. In Oregon—Mt. Hood and in California—Lassen Peak.
There are dozens of small volcanoes (like my Mt. Konocti in Lake County) around this region that are also listed as active.

North of you in Scandinavia you will find lots of younger mountains and volcanoes and fair amounts of obsidian.

And of course Iceland, like the Hawaiian Islands IS basically a volcano top.

This concludes today's little lesson on volcanoes.
Class dismissed

Thanks hermit, that was as interesting as all your posts. Can even remember the eruption of Mt St. Helens, I was 10 years old but the picutres shown on tv left a massive impression on my mind.