What is this?
Mon Sep 03, 2012 4:09 am
I found this in today. I live in Florida and we don't see these type of rocks here. Can you please tell me what it is. I found it in my yard. Looks volcanic to me 
Heat and pressure 
Might find them everywhere at another latitude but not here.
Heat and pressure Might find them everywhere at another latitude but not here.
Re: What is this?
Wed Sep 05, 2012 4:01 am
It is really beautiful ,and I think it must be some pieces agate .it's major ingredient is SiO2 ,always formed in the area covered by effusive rocks .
Re: What is this?
Wed Sep 05, 2012 8:43 am
First impression: It is a concretion, hence formed in a sediment. Second: it might be simply chert. Although this is alsao quartz, or if banded: agathe, as suggessted already. Does it break like glass?
Rien Nederlof
Rien Nederlof
Re: What is this?
Mon Sep 10, 2012 12:47 pm
Re: What is this?
Mon Sep 10, 2012 1:57 pm
I meaqnt that when you hit it with a hammer, it may fracture. Flint, quartz, obsidian and glass have a characteristic type of fracture, quite unlike crystalline materials, such as calcite or mica.
Re: What is this?
Tue Sep 11, 2012 6:44 pm
I haven't busted enough rocks to recognize this (speaking literally). Although, I would observe the obvious fracture that is aparent and guess that it apears to my "inexperienced eye" that it does indeed break somewhat like glass.
Thanks for all the help.
rock on
Thanks for all the help.
rock on