What type of mineralisation is this?

[Frank D.]

I dug a little bit at a creekside and found this type of mineral holding different rocks together almost like a weld. It's black and sooty looking with a little bit of a silver metallic shine due to some particles throughout that are silver in color. Anyone know what this is holding the rock together? Most of the rock looks to be decomposing schist that I think is the bedrock. The other rocks welded to the schist seem to be quartz and quartzite. The quartz and quartzite seem to be more like rock I see on road construction sites in that type of gravel. Thanks, Jay

 

[Eu_citzen]

It is probably limonite holding it all together.

 

[Frank D.]

Thanks Eu citzen. I didn't think of Limonite because I have only found it down stream and already mostly worn off it's host rock. It's like the whole area under the dirt and water level is welded by that stuff where I found this. I had to use a prybar to get some of it out.

 

[Turkısh Man]

Ferrous manganese ore

 

[Eu_citzen]

Limonite can precipitate out of water, so being near a stream makes sense. (some iron ions are water soluble)

 

[Frank D.]

Thanks guys, much appreciated!