help identify please

Location Rocky Glen Sandy Hook CT
on a steep slope of the loose rocks or tailings of the old Gold and Silver mine.
unusual since there is nothing like it anywhere else in the area, and this was in an area that very few would venture up on to.
I don't believe it is coal.
Makes no sense for this area,
The rock is lightweight.
Shows some large flat shiny surfaces,
any suggestions?

Does seem odd. How light? Can you weigh it and see how much water it displaces, and get it's SG? Maybe slag, if there are air bubbles. Nothing lightweight is cubic that I know of.

Mike

Many mines had coal stoves to keep warm in the winter, I've found coal in old dumps before, along with bricks,
metal and thin glass used for windows in the old mine shacks.
Can you scratch it with a knife?
What color streak does it make?
Can you get a small piece to burn with a torch?

Hi Wayne,

There was period in New England and other areas that Steam Drills were used
at many mines and quarries.

Cliff

weight 225 grams/ 7.8oz
2.5" X 2.5" X 3" dimensions

can scratch with knife
leaves black streak

The slope was 45 degrees and had lots of loose rock, quartz everywhere,
No signs of furnaces, or bricks, or even a trace of other coal in the area.
it was the flat shiny surface like that of a Shorl Tourmaline that had me guessing,,,
Of all the local mines and pits that had furnaces, this is the first we ever found a piece of coal if it is,.,.

just thought is might be graphite, another form of coal,,,,,



Edited 1 time(s). Last edit at 02/22/2012 02:39AM by Dennis Cartolano.

This appears to be serpentinite, likely composed mostly of antigorite serpentine. Very common near the gold mines in my area.

Dear Dennis,

Try as I might, i could find no location as you gave, for any mine. There were mines south of where you said, but, weren't that close to where you said this specimen came from. I also did my "increase view" trick, on your piece, &, believe you have a "transported piece", meaning, it didn't come from that area & was brought there as fill. That means, there's no way to determine the possible choices, simple by giving the location, bcs, there's no real way to determine that, accurately. To help us help you, we need more descriptive info, using some simple tests, which, are given as a tutorial on the "identification forum". Please go there, learn some of the tests you can do, to give us better info.

That being said, I most congratulate you for trying to give us as much info, that, ordinarily would have helped, as you did. Also, from the apparently good (though, not great) cleavage planes I see in the photo, I would discount that as being a tourmaline; just not sure what it is. NOT slag. My VERY tenative guess - a feldspar or cordierite.

Your friend, Steve

Does it burn? A good test for coal!

If I read this correctly, this piece was found in the ravine, known for the Sandy Hook Gold Mine. I uploaded some pictures of it some years ago. The gold was most likely salted to fool investors although there is a sign at the base of the ravine noting that gold was mined and found there.

Can't help you with your piece but thought I would contribute a little about the locality. The adit was filled in with all kinds of junk so just about anything might be found there, coal, slag, etc.

Hi Dennis,

It's hard to guess from an image alone. It looks like Augite to me but could easily be something else. The approximate streak and hardness you mentioned seem somewhat compatible with Augite. The specimen seems homogeneous, that is likely all the same mineral. If so, you should measure the specific gravity (density). Augite density can be somewhat variable, ~3.3 g/cm³ but about twice as dense as coal. Here's a link to another thread that discusses some methods to quickly determine specific gravity of a specimen. [www.mindat.org] Once you know the specific gravity you'll be in a better position to ID this rock. Good luck with it, let us know how it works out.

Ron