ThunderRock 0 Posted June 28, 2015 this is given to me via an inheritance so I don't know where it came from it looks like it has dark red blood cells almost in it can't decide if it's bone or tree. any ideas? thank you in advance for your time. Share this post Link to post Share on other sites
Plantguy 736 Posted June 29, 2015 I'm thinking this is one of the cool metamorphic rocks from Northern California and its not a fossil. I believe the reddish areas are actually garnets...Rock type could be one of the schists that are common in the Franciscan Complex rocks in the SF Bay area. Is there any neat story/info that goes along with the inheritance as to where it came from and why it was collected? Is it from Northern California? I have a small sample I collected with small garnets from Marin County but it has more of the greenstone/serpentine like minerals in it that are also common from the region. Regards, Chris Share this post Link to post Share on other sites
Trickworm 15 Posted June 29, 2015 Looks like some kind of schist like Mica Schist with garnets like Plantguy said. Share this post Link to post Share on other sites
Taogan 217 Posted June 29, 2015 Make that three for garnet schist Share this post Link to post Share on other sites
Mike from North Queensland 382 Posted June 30, 2015 Make that 6 as the red blotches look 6 sided. Pity they are not gem quality. Mike Share this post Link to post Share on other sites
DPS Ammonite 3,367 Posted July 4, 2015 This rock does look like it contains garnet. However, it does not look like any San Francisco Bay area rock that I have seen or heard about. Most of our garnets are less than 4mm, while your rocks contains garnets that are 2-3 cm. Bring this rock and any other rocks and fossils to the Northern California Geological Society meeting in Orinda, CA on Sept 30th, the next meeting. See: www.ncgeolsoc.org We will be happy to look at your rocks to give them an ID. Cheers, John Share this post Link to post Share on other sites
Plantguy 736 Posted July 4, 2015 This rock does look like it contains garnet. However, it does not look like any San Francisco Bay area rock that I have seen or heard about. Most of our garnets are less than 4mm, while your rocks contains garnets that are 2-3 cm. Bring this rock and any other rocks and fossils to the Northern California Geological Society meeting in Orinda, CA on Sept 30th, the next meeting. See: www.ncgeolsoc.org We will be happy to look at your rocks to give them an ID. Cheers, John Hey John, was hoping ThunderRock could provide some provenance on this rock. Would be really interested to hear anything more and if you all get to see the specimen as well. Good point--Agreed the garnets are large and they can tell you alot about the rock's origin. Years and years ago in Tiburon there were some eclogite? outcrops and some other really messed up metamorphic rock types with garnets and over in Berkeley as I remember.. Let us know if you find out anything more! Regards, Chris Share this post Link to post Share on other sites
