[Geology2] re: very interesting mystery rock

If it were a crinoid, then perhaps it is the holdfast rather than the calyx.

The over all impression of the "mineral" is specular hematite. I don"t recall seeing hematite replacement on that scale. It does occur in ordovician/slurian sandstones, limestones, and marbles here in Tennessee. A streak or specific gravity test should confirm if the matirx is hematite.

Elton



------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/geology2/

<*> Your email settings:
Individual Email | Traditional

<*> To change settings online go to:
http://groups.yahoo.com/group/geology2/join
(Yahoo! ID required)

<*> To change settings via email:
geology2-digest@yahoogroups.com
geology2-fullfeatured@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
geology2-unsubscribe@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/