Driftwood + Limestone | Schoharie, NY, The Story of a Quarry and Iron Sulphate Fossils – Part II

One of my favorite things about my pigment work is the new information that I learn, artistically, culturally and scientifically. As i mentioned in Part I of this story, I came across these beautiful little iron fossils upon closer inspection of the landscape near the quarry in Schoharie. At first, i wasn’t sure if they were fossils or simply pure iron ore, until getting home to do some further research. What prompted my intrigue in finding out some answers was also the presence of Pyrite that was centered around the rich iron colors on the surrounding rocks. This Pyrite was the key clue to unravelling the interesting little mystery of my find.

First, to understand how these once living organisms transformed into the present day beautiful nuggets of color that they are, we need to know about the process of fossilization. Fossilization is the process in which mineral deposits form internal casts of once living organisms. The minerals are carried by water and fill the spaces within organic tissue by seeping into the pores of the cells wall and form crystal structures within the walls – the cell walls remain intact surrounding the crystal.

The presence of Pyrite in these color samples indicate that the water and sediment they were once submerged in was rich and saturated withe Iron Sulfides – as Pyrite is an Iron persulfide (FeS2).  Pyrite is often found in sedimentary rock – as organic matter decays it releases sulfide which reacts with the dissolved iron particles in the water.  Pyrite replaces the once carbonate shell, bone or structure of an animal or plant due to an undersaturation of carbonate in the surrounding waters. This occurs frequently in marine environments and is a process of Permineralization.

When these Pyrite fossils are exposed to O2 and H2O they can suffer from “Pyrite Disease” or “Pyrite Rot”. This “disease” is actually the oxidation of the Pyrite which in turn transforms it into Iron Sulphate (FeSO4).  The product of the oxidation is several times the volume of the original material which causes the fossil to fracture and crumble [1].

Upon crushing down some of the less discernible and more damaged specimens for a truly unique pigment, they released a strong sulphur smell as they were still pure pyrite in the core where water and oxygen had not yet penetrated. The pigment, as it stands now is a rich brown color – but will transform over time and exposure to the orange-red rust tones we come to know with oxidized iron.

Due to the scarcity of these fossils at this site and sustainable color foraging practices – I will only be making a small amount of this pigment from what I collected. Once sample will be archived, one small sample will be used in a fine art piece to tell the story of the land from where these came, and the other 2 dram vial will be sold in the shop soon – 100% of the proceeds from the sale of this pigment (which will include some other little treasures collected from this spot) will be donated to SOS to help their fight with the expansion of the quarry.  If you are interested in purchasing the pigment and supporting this cause before I have the chance to get the store up and running – please email me at [email protected] for more information. Thank you and much love and light to you and yours !

Please see the links below for further reading on the topics mentioned in this post :

Pyrite | Formation / Oxidation

Pyrite Disease [1]

Pyritization 

Permineralization