This unique semi-organic mineral structure is the result of a slow chemical reaction. The reaction occurs spontaneously between alkanethiols, which are simple sulfur-containing organic compounds, and lead oxide. Here, the oxide is a surface coating on a coil of metallic lead wire that forms naturally in moist air. The structure consists of layers of lead alkanethiolates, a stable compound that is solid at room temperature and has a distinct yellow color. The layers grow outwards from the surface of the wire as the reaction proceeds, curling into �petals.� But be careful, beautiful though it may be, this �flower� is toxic. The structure grows slowly upward as the wire is uncoiled by the growing petals, eventually filling the jar in which the reaction occurs. This structure took more than a week to grow. A less delicate but faster growing form of this material can be used to remove polluting sulfur compounds from gasoline during the refining process.