What Is This? Bright Silver In Rock

[Rods]

any idea what the material / mineral it is?

it`s very shiny, the green reflections are from the plastic lid i had them sitting on

[Reno Chris]

Its hard enough to tell minerals just from photos, but when the pics are blurry, that's even harder. Just a raw guess is that its galena, a common mineral that is the most important ore of lead. Any chance of a better picture?

[Jeff McClendon]

Hi,

Reno Chris had a good guess. That was my first thought too. It is hard to see the broken surfaces of the silver mineral. That would be key to confirming galena or hematite, goethite or something even more interesting. A clearer close-up photo would really help along with where you found it.

 

Jeff

[oldmancoyote1]

The presence of iron rust strongly suggest specular hematite.

[Jim Hemmingway]

Hi Rods… welcome to the forum!!! 

Your rock presents an intriguing identification challenge for us because you’ve provided no information about it. For example, is there a mining history where it was found, did it respond to a metal detector, does the mineral feel weighty for its size / volume, is the shiny substance on your rock flexible or rigid? Or is what we see a result of light reflection as it pertains to the camera to sample angle. You see the real thing, we have to guess at what is real in the photo.

Would you mind doing a simple streak test for us? It takes only about 10 seconds to do. The streak test involves lightly running the “shiny” substance on your rock across an unglazed white porcelain tile. In a pinch you can try rubbing your sample across the unglazed bottom surface of some coffee mugs or whatever is available around the house. With dark minerals, the color of the streak can be quite different from the mineral color, thus providing a very useful clue as to its identity. 

A streak test can readily eliminate a number of possibilities. Goethite produces a brown-yellow to yellow streak. Various forms of hematite can produce a range from a bright to quite a dark cherry red streak. Galena produces a black streak. Silver produces a silvery streak. And there are other possibilities, but there is no mistaking the difference in streak results between the minerals suggested above.

Below are photos for the above suggested minerals. The goethite has a weathered surface, but look at the small exposed area of black lustrous material to see what actually exists beneath the surface. Note that galena has a distinct “grey” color and metallic luster. 

Specular hematite is a little more difficult because its uneven or crystallized surface makes it impossible to avoid light reflection from many faces. It is generally lustrous, but it is also primarily black. It can readily be distinguished from other similar-looking minerals such as ilmenite and magnetite by its red streak. 

Hopefully the photos will be of some use for you to compare to your sample. Let's add a molybdenite (a flexible mineral) photo just in case. But please consider doing the streak test and let us know the results if that is convenient for you……………….Jim.

[Johnnysalami1957]

I'll ask this woman I know. Her name is Goodntite.