Iron is the oldest and most versatile of all the potter’s pigments. Iron was an easy choice for early decorative application because it occurs naturally in most clays, is easy to isolate, and applies easily. It is one of the most abundant materials on earth. Today, potters have a nearly unlimited array of color pigments to choose from. But Iron provides the widest range of color a single element can offer. Black, blue, green, red, yellow, brown, almost any color but white. The Digitalfire Ceramic Materials Database indicates Iron, being non carcinogenic, is considerably safer to use than many other metallic oxides used in ceramic color formulation. (But too much of even a good thing can be hazardous…)
Iron has been good to pottery and pottery has reciprocated. Iron (and Bronze before it) propelled the great Ages of civilizing progress towards the mess we now live in. But there had to be a Pottery Age first. Forges and furnaces are impossible without a working knowledge of refractories.
Iron (Fe, atomic weight 26) occupies a special place on the Periodic Table of Elements. Smack in the middle of d-block’s transitional metals. This position allows Iron a phenomenal degree of versatility. With a perfect balance of protons to electrons, Iron provides a very stable environment to attach, then drop off catalysts when necessary. Potters know its crucial role in reduction atmospheres during kiln firings. Iron transports Nitrogen to where it is needed as a fertilizer in soil. Oxygen easily sticks to Iron molecules, and as easily drops off when needed in the blood system. And of course by varying the amount of oxygen mixed with Iron in a forge, steel results.
And so on, and so on. Yes, a very handy element indeed.
So when Newton’s Second Law of Thermodynamics – increased entropy – is applied to Iron in relation to the entire universe and everything in it, a curious possibility presents itself. Unless any number of other things destroys the universe first, it can be assumed that all matter will eventually disintegrate. But because Iron’s nucleus is so powerfully bound together, it will be the last element to exist. Anywhere. After that, all will be simply radiation.
Quite an image.
Readings:
Periodic Kingdom. P.W. Atkins. Harper Collins/NY. 1995.
The Emergence of Pottery. William Barnett and John Hoopes, ed.s Smithsonian Institute Press/Washington DC. 1995.
Clay and Glazes for the Potter. Daniel Rhodes. Hilton Book Company/Radnor, PA. 1973.
This Day in Pottery History 
