[Rockhounds] Florida silicified shell fossils

[Alan Silverstein]

Howdy folks.  A year or two ago, there was some chat here about
silicified Florida (USA) shell fossils -- not to be confused with
well-known Tampa Bay area agatized coral.  I mentioned that I'd
collected a handful in North Miami Beach back in the 1970s.  Here's a
recent photo of them:

  http://silgro.com/pics/171103_NorthMiamiBeachRocks.jpg

Also I talked with someone off-list about these rocks, but then I
couldn't find the originals in my growing collection!  Well recently
while doing sorting and high-grading, I found the flat, and this is what
they look like (photo URL above), with a penny for scale.  Note that
some broken pieces show yellowish quartz crystals inside.

The two-sided bivalve cast on the right end of the third row is the
coolest...  It's translucent when you hold it up to the sun.

I wish I'd spent more time back then collecting on this scraped-off open
field before they built a suburb on top of it!  Just from memory, I
think the location was around 25.95397 -80.16272; paste into Google Maps
to see where.  While I know it was west of some like in the area, not
sure I have the right one!

Cheers,
Alan Silverstein