A Blog Around The Clock : A Question

Genetic Future

Profile

My scientific specialty is chronobiology (circadian rhythms and photoperiodism), with additional interests in comparative physiology, animal behavior and evolution. I am not an MD so I cannot diagnose and treat your sleep problems. As well as writing this blog, I am also the Online Discussion Expert for PLoS. This is a personal blog and opinions within it in no way reflect the policies of PLoS. You can contact me at: Coturnix@gmail.com

Join us at ScienceOnline'09

Buy the 2007 Science Blogging Anthology:

Buy the 2006 Science Blogging Anthology:

Subscribe via Email

Stay abreast of your favorite bloggers' latest and greatest via e-mail, via a daily digest.

Sign me up!

My Old Stuff

Make Me Happy

Add Scienceblogs to your Technorati Favorites!

Make Me Solvent

I Support

Bloggie Stuff

This work is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported License.

« Tripoli Six Update | Main | Edwards and Edwards »

A Question

Category: Physiology
Posted on: September 24, 2006 9:41 PM, by Coturnix

My sister in law is an artist and is writing a proposal for funding a project. She intends to use red clay to make some figurines. She has heard an old story that the composition of red clay is similar to the composition of the human body and is wondering how much off the mark is that statement. I am pretty sure that at the level of molecules/compounds the difference is huge, but I am not sure how big is the difference if one breaks down the chemical composition down to elements/atoms. I suspect that carbon and hydrogen may be close, but how about nitrogen, oxygen or, even more difficult for me to find out: copper, phosphorus, iron, sulphur, manganese, etc.? Do you know?

Comments

I don't know much about human body composition (other than there's a lot of water) but I doubt there's a close relationship between clays and living organisms. The chemical formula for the most complex family of clays, montmorillonite, is

X0.2-0.4 Y2 Z4 O10 (OH)2 * nH2O

where X is some combination of calcium and sodium, Y is some combination of aluminum, magnesium, and iron, and, z is some combination of silicon and aluminum.

Other clay chemistries are basically reductions of this. Red clay would undoubtedly have a fair amount of iron in the Y position. But no carbon, lots of silicon and aluminum, and enough iron for a red color (which actually doesn't take a whole lot). *

If this is similar in composition to the human body, I'd be very surprised. Just as a guess, I'd say the story came about because the red color reminded somebody of blood.

* source: Perkins, D., 2002, Mineralogy, 2nd ed., Prentice Hall, Inc., p 313.

Posted by: Karen | September 24, 2006 10:26 PM

The information on Wikipedia seems to indicate the same: That there isn't very much similarity.

See:
http://en.wikipedia.org/wiki/Clay
and the various links listed therein.

Posted by: Chris | September 24, 2006 10:39 PM