Even though the chemistry part of this article made me throw up in my mouth a little bit, I really found this article interesting. This article discusses how skeletons of organisms contain small amounts of different impurity elements. These elements are used to get an idea of what environements in the past were like, and where the particular organism being examined lived. Researchers found that simple peptides and proteins could be altered to control crystal growth and the rate of crystal morphology. Then the researchers learned that biomolecules have water structuring abilities and this could influence the amount of impurities that can go into a mineral. A hydrophilic peptide can also enhance the magnesium content of calcite. The organisms use proteins to grow minerals into different shapes. The magnesium content increases with temperature but biomolecules can also effect the shapes. This has also shown new ways at looking at skeletal mineralization and if the local biochemistry could influence if toxic metals can go into human skeletons.