4meter

I'm with Bob on this one. Just from the photos, it looks like an impure meta-quartzite to me.

I' so glad the Bob used the "A" word. I alluded to "A-tos" minerals but did not want to use the "A" word and have folks freaking out ; like my roommate back in college when he learned that the pretty green fibrous mineral (Chrysotile) on my bookshelf, with the other rocks, was an "asbestos". It was in a clear zip lock baggy by the way; still is.

Sure looks like the lip of a pot/jar to me. It could be a pottery shard, where the pot was made with mineral fibers (actinolite, tremolite serpentine) in addition to clay to make it heat resistant.

Very cool piece. I wonder what the white, round, mineral is? Sort of looks like Smithsonite. The green mineral has an unusually high luster to it, more than I would expect from Malachite. I'm not writing off Malachite but I wonder if it is not another copper mineral. Does the high luster green mineral fizz in dilute HCl?

Quartz with iron and manganese stained mini "Geodes" inside. Coll piece! I have also heard these called "Box Work" quartz.

Piece of quartz.

Looks like poorly preserved tabulate corals from the photos.

Very nice samples! One day my Tourmaline will come. O Schorl ! Looks like this is not the day.

Yep! it has quartz in it. Appears to be a water worn "cobble" derived from a granite (rock type) source. Nice looking sample!

Defiantly not a meteorite. Not sure what it is from the photos. More info would help like streak color, tenacity, better photos.

Interesting looking sample but we need more info. How heavy is this sample compared to a equal size of Quartz? What is the hardness, streak color and tenacity (ductile, malleable, sectile, flexible, brittle or elastic) of the black/gray material? Just from the photos I would say it is Quartz with Manganese stains ( Psilomelane and/or Romanèchite) and iron stains.

Heavy and from the shore or Maryland would rule out coal & obsidian. I think it is glass or slag, probably used as erosion protection. Check the hardness; coal has a hardness of 3, glass or slag ~ 5.

Cobble or a boulder; depends on the size. Made of ? Photo does not provide enough detail.

Check hardness of sample(s). Anthracite has a hardness of 3. As you can see from this video clip Anthracite will ignite but it takes some patience.

A simple, quick, streak test (use an unglazed, white porcelain tile) will distinguish Pyrite from Gold. Gold gives a gold colored streak and Pyrite produces a greenish-black colored streak. Gorgeous country to me mineral hunting in!