Black shells

[mick]

I'm seeing a few mainly scallop shells that are died black, there are no scallops here with a natural black shell.
I figure they have been in the peat that underlies the sand here and eroded out.
So how many years do you think it would take to turn a scallop she'll black from peat staining?
It must be a long time, the shells are harder than concrete.
The peat is from millions of years ago, it's linked to the brown coal up,the road.
One other thought, they maybe an already black species from eons ago and the peat has just made me blacker?
Whattaya Think?

[rocks2dust]

Scallops in both Atlantic and Pacific can have near-black shells (usually on the top side for camouflage in areas with dark seafloor). So, in many areas it could have been the original color. But if not, I expect that natural shells could easily be dyed using the same techniques used to dye marble, travertine and calcite. Fossil shells can also be quickly dyed, either naturally or artificially, just as can limestone, agate and opal. Darkening from peat would be faster than some other mechanisms: anywhere from several months for just the outer surfaces, to several decades to penetrate throughout a larger, fully agatized/opalized piece. Peat is acidic; so would speed the process.

[SwordfishMining]

Probably natural coloration. Here where the opal beds thread out into lignite we will get hydro carbon staining that we call fools opal. It has the look of oil on water. Real colorful like titanium treated quartz color spectrum. The opal is un colored in it usually, tho. Weathered out potch and woods can get "desert varnish" which is a chemical coating of essentially black potch from clay, water, minerals from evaporation combine over decades in the sun on the exposed surface. Thats always detectable by exposured find or in situ. I was thinking somebody was putting "boot black" on shell patch crystals or natural manganese stained matrix had been discovered.

[PinkDiamond]

Nice information here, guys. Thanks for posting about it mick.