weird black rocks

[shaman15771]

on our land we have two creeks. one that runs intermittently and one that runs all the time. what I would like to know is why the rocks in the big creek are all covered in black. I thought maybe a forest fire, but even the undersides are black. this is a coating on the rocks they are not naturally black.

 

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[TxFlag]

Sounds like manganese-rich rock varnish.

What is the black on the rocks?

 

[BurntBear]

Here is a link to show you mining sites in Virginia. Look in your area and see what kind of mine production is nearby. This should give you an idea on what types of metals are in your locality.

Virginia mining, mines, mine owners and mine statistics

 

[shaman15771]

Thanks BB! That helps a lot although doesn't cover gemstones. Got mica, silver, gold, iron, cesium, quite a few different things. I do know from research that we've got two beryl mines nearby, tourmaline, muscovite, corundum and zircon. Very highly mineralized, quartz has a lot of yellow/orange mineralization. And is seems every other rock I pick up has garnet. Some deep red, some bright orange (beautiful). Also have galena ore.

 

[BurntBear]

I would be digging!

 

[Brian T. Booth]

on our land we have two creeks. one that runs intermittently and one that runs all the time. what I would like to know is why the rocks in the big creek are all covered in black. I thought maybe a forest fire, but even the undersides are black. this is a coating on the rocks they are not naturally black.

TxFlag is correct. It's manganese oxide.