We Found An Interesting Rock.. Please Help ID...

[russellx]

My kids and I were throwing rocks into a little pond the other day and we think we may have found an interesting rock..

my neighbor works at a chemical company and offered to run it under an x-ray spectrometer, and it dont ~think its magnetite...

I would love if you could take just a quick look at these pictures and let me know your thoughts... and I am fully prepared
to hear its a perfectly normal rock..

Thank you so much for your time...

here are the results;
AL203 12 %
SiO2 19 %
K2O 1.98 %
Fe203 66.09 %

trace amounts
CaO .17 %
CuO .037 %
Cr203 .065 %
MnO .061 %
CuO .037 %
Br .076 %
Rb2O .081 %
RuO2 .03 %
Sb203 .03 %


here are a few more angles, didnt want to embed them all in case someone has slower internet speeds..
delawaredb.com/rock/DSC04242.JPG
delawaredb.com/rock/DSC04244.JPG
delawaredb.com/rock/DSC04245.JPG

[raleighrocks]

For anyone to take a guess they will probably need to know what state and region you found it in, i am no good at mineral identification but that is one strange looking rock. good luck

[russellx]

oh, your right, I did forget to add that...
Im located in the northern part of Delaware, just south of Philadelphia..

edit:
one other thing I forgot to mention....
I did do a streak test on the back of a toilet lid..

one side streaked reddish brown.. while the other was completely clear....

[leonardo]

Looks like a vug with crystals in it bottom-middle

[arappaho]

WoW, we could all use a neighbor like that! That's Awesome!
And what a great job of posting a rock for identification!
I don't think I've ever seen better, Russel.
I was going to leave this for some of the folks from that area to
reply to, but I had to thankyou for the great job.

My guess is that it's a segment of a very ferruginous (iron) layer
of sandstone. Sandstone is usually cemented by silica or calcite,
so this would be silica. That's where and why the little vug with
crystals Leonard mentioned was formed. If you get out the geology
books for that area the silica cement will help to date and name
the formation of that particular layer. The reddish-brown streak is
textbook for hematite or iron oxide. The area that produced no
streak probably had more silica, or quartz, in it.
I don't know what it is about the geology of that area that would
cause all the Aluminum precipitated in the stone.
If you are looking for a name for the rock, and if it is what I'm
guessing, then you would be looking for the name of that formation.

Just my two cents and thanks again for a great post.
Hope this helps,
Joe

[eechler]

Not sure what the rock is. but it look like asbestos fibers on the bottom.

[justarock]

kind'a looks like Limonite. mostly iron and some of everything else.

[justarock]

Oh, and the streak is always brownish.

[leonardo]

I thought limonite was from pyrite.....and the fibers under the rock is wood....

[rocksmarsandstars]

Top part looks a lot like the limonite I find when looking for pet wood here near the Cape Fear river-the botton part looks like a small pebble-sized conglomerate deposit. Esp. given the high % Fe2O3 conc.
Ken

[russellx]

thanks for your ideas guys,
and yea, the fibers are a stick I used to prop it up and get that angle...

my neighbor... I agree, he rocks.. LOL how bout that pun...

man.. this really has turned out to be an interesting rock (for me anyway)..

I think a new rockhound has been born....

[mikeyrocks]

Heyy russellx, Not sure what it is.... I was from that region...Philly. One of the groups to consult just to the south of you is the Delaware Mineral Society; a good group of people. Stop at a meeting and take it with you. Tuscarora Lapidary Society is also not far (my former club which was in Media, PA) another great club to join. You do not need to join to stop at a few meetings and ask questions... they like visitors. enjoy!