don't know what this is.. do you?

[lynskyn1970]

hey everyone, my husband found this chunk of rock in our pile and i was like wow really nice stuff, then i noticed that speckled here and there in the cab he cut is some type of metal. it appears to be a gold color. upon inspecting the rough rock i noticed more metal in it. i'm really not sure where this rock came from due to the fact we got a bunch of rough from an estate sale and the owner of the material has passed away. i think it was in a bucket marked "mexico" but not positive on that. well the rock isn't too hard it is softer than agate maybe a 5 or so on the mohs scale.
the metal flecks are on the lower left hand side and also the upper left side and a speck on the right end.
as you can see there is the metal showing through the stripe of light color in the middle.
no metal showing on this pic. thanks for any input you all may have on this one!!!!

[nose2ground]

first question would be how soft the metal is - can you scratch it off with knife, or is it as hard as the rock. My suspicion would be pyrite grains, which would be hard, brassy gold and shiny. Could you get a separate streak from any of the metallic parts?

Mexico pile - looks like onyx - maybe onyx with pyrite inclusions. Neat find.

[lynskyn1970]

i'll have to check the metal for it's hardness. haven't done that yet. my first thought was pyrite also. who knows? pretty though. i have several pieces of this material laying around i'm gonna check them all to see if the other ones also have this metal in them. thanks.

[gemlover]

if you can streak on unglazed ceramic and get black streak, then almost guaranteed to be pyrite. with a loupe, are the crystals cubic? then also almost guaranteed to be pyrite. if flat and hexagonal, most likely muscovite mica.

John

[arappaho]

It looks like gneiss or rhyolite to me.
My first guess would be rhyolite because of the way the surface breaks
look in the second picture.
Pretty stuff.

[lynskyn1970]

well thanks guys i'm still leaning learning toward pyrite also. well i can't tell the crystal structure due to not having a loupe to look with. also i tried to scratch the metal spots with a knife and it doesn't scratch real easily. can't do streak test on metal parts cause they are too small of an area. almost seems to me that the rock and metal are very close in hardness. i also have other pieces that appear to be the same except they are much lighte in color. i'll have to go and cut one of these lighter pieces and see if there is metal in them also. i'll post pic of the lighter material soon.

[turnedstone]

Hi lynskyn looks like banded slat to me.Just seen the same material this past weekend at the flint ridge Knapp- in it matches this dead on. George

[lynskyn1970]

wow thanks didn't even think of slate. could slate have metal in it?

[nose2ground]

I don't have a lupe either - but if you have a picture editing program (e.g. GIMP), and get the pic in good focus using a low ISO, you can zoom in very close with the program and see things you would not be able to see otherwise. Did that with a piece of limonite/pyrite and was able to easily see the garnet crystal - all I could see with my eye was a teensie speck of pink-purple.

[lynskyn1970]

got to fiddle around someway with the photo editing software on this darn computer. i am sort of familiar with gimp. i'll have to recruit one of my brainy kids for help!!!! also my kids have a microscope i'm gonna try to see the rock with that. maybe take a picture through it..... mmmmmmmm this will be interesting!!!!!

[abuelito]

i was told its a silicate highly compressed,i dont know because i am not to smart,this material found on highway cut from victoria to san luis potosi,mexico polishes out nice,,,,,ab

[lynskyn1970]

intersting material. i like the contrasting stripes of colors.