4meter

The black flaky minerals are biotite, the gray, "glassy" mineral is quartz, the yellow/brassy colored minerals that pepper the sample is pyrite and the flat yellow minerals are either muscovite or phlogopite. You are the proud owner of a schist (metamorphic rock).

Is this the same sample as in first picture, just split open?

Cool looking sample! Here are a few guess that might help pin it down. Massive augite, massive hornblende, anthracite coal & pitchblende (uranium ore), just to name a few common black colored minerals. The last one named, to test for uranium, put it next to your goldfish and turn off the lights. If the fish glows its pitchblende; just kidding!

The white sample looks like box-work quartz, calcite or possible feldspar.

Woo, lets stop right here with the Tektite idea. Tektites are glass formed by the melting of terrestrial rock during the initial stages of an impact crater formation. They are black and glassy because they are glass, similar to obsidian. None, to very minor amounts of iron are in Tektites. I'm no expert on impact craters but your "Tektite" pictures look nothing like the samples I have seen in privet and academic collections. Terrestrial astro blems, as impact sites are know, are so rare that to find anything created by such an event is highly improbable. That is unless your on the m

Funny that another member posted the photos of the garnet ball, as I have garnet photos to post. I was walking a wash on the North side of Tucson today, when I came on some quartz and feldspar fragments that had been transported down from Mt Lemon. I picked up several pieces, planning to cut these into squares and turn into thin sections to use with my new polarize microscope. After cleaning the samples I had a look under my 20X/40X bino microscope. I first had a look at a plagioclase feldspar sample. To my surprise I saw all these beautiful, small, honey-orange garnets. They are the

It is a Garnet Ball; that is a lot of garnets all grown together. Many of the outside minerals show the classic dodecahedral shape. Might be the iron rich, almandine variety of garnet.

I think it is a sandstone with desert varnish on the outside. The "varnish" has been mechanically worn off producing the "tiger strips" pattern. Neat find! Desert varnish = a chemical weathering process that produces a dark "rind" on the outside of a rock, exposed to a desert/semi desert environment.

Its a chunk of granite. The green staining is most likely algae. Try soaking the sample in some strong ammonia (not Windex) for a few days, the green should come out.

Last photo looks like a metal ore of some type. Can you do a streak test and let us know what color the streak is? Compare the "weight" of this sample with a similar sized chunk of agate you have. Hold them at the same time, in different hands, and bounce them up and down in your hand(s). Which one is heavier and give an approx ratio of the heavier one. That is the heavier one is 1, 2,4,6... times heavier than the lighter one. Better photos and close-up photos would be great.

Sorry to say, but that is not a Dino bone. It belongs to a mammal of some sort; most likely a cow or horse. Not a very old bone either.

You have Quartz. The brownish/red color on the outside is due to iron staining the quartz.

Obsidian, a natural volcanic glass.

A very interesting sample. It is not a meteorite and not ore. I think it is a partial refined metal of some sort. Maybe a tungsten or manganese alloy? What sort of streak does it produce and how hard on the mohs hardness scale is it?

Try putting some warm vinegar on the sample to see if it fizzes. If it fizzes its limestone. If no fizz, then it is something else. I'm thinking this sample is a vesicular basalt (igneous rock which had lots of gases that left lots of bubbles holes once the lava cooled) where the holes (vesicles) were later filled in by quartz or calcite. The filled in holes are called amygdaloids.