Petrified Wood/Glitter Odd shaped Rock

[roustabout149]

These are some of my very first finds in the 90's. I have the tendencey to pick up everything. The petrified wood is sort of a silvery white. The rock is glittery black which I don't believe can be seen in the pictures. I'm not certain what the rock is, other than an odd shape. Possibly sandstone?; I've been very careful with the black rock all of these years as not to break it. One of the edges crumbled soon after I found it therefore I stored it away!

[Pullenrock]

Some big ole rocks..the glitter must be formica?...

[roustabout149]

Formica???  Drug out my old rock book.  Love those rocks!  I found what may be my find.  What's your take on it?  Maybe?

[Pullenrock]

Gosh! not sure...Rocks?....I loves em too...Here before we came here after we leave...Looks like a soft granite unh?

[Scorpion68]

Pam - Did you say it crumbled.  That's a trait more common to sandstone.  Granite is a harder, more packed rock material that doesn't usually crumble, at least not the granite that I'm used to finding.  The sandstone will usually have lots of mica or crystal type particles in it that makes it sparkle.  ---Chuck

[roustabout149]

Chuck, I did say it crumbled.  The piece is exactly how I found it, with the exception of the thinner outter edge which I referred to as crumbling. As thin as it is, it may have just broken off.  Definition from the book:
Texture:  Commonly phaneritic, medium-to coarse-grained, occasionally porphyritic with phenocrysts of well-formed crystals of potash feldspars (orthoclase or microcline with Carlsbad twinning).
Now, that's all Greek to me.  What I get from that is the well-formed crystals, which I do understand, are the sparkle.  I'm not 100% sure that it is Biotite granite, but the rock is hard and is definitely not sandstone.  Whole different ball game there.

[Scorpion68]

Pam - Might be right.  I've worked around Granite, Marble etc for a number of years and have never come across a Granite that crumbles.  Live and learn - I guess.  ---Chuck