Ductility
Ductility can be quantified by the fracture strain formula_1, which is the engineering strain at which a test specimen fractures during a uniaxial tensile test. Another commonly used measure is the reduction of area at fracture formula_2. The ductility of steel varies depending on the alloying constituents. Increasing the levels of carbon decreases ductility. Many plastics and amorphous solids, such as Play-Doh, are also malleable.
The most ductile metal is platinum and the most malleable metal is gold.
Lithium as an investment
Lithium metal is an extremely soft, highly reactive, and flammable element. It is most frequently found in deposits such as spodumene and pegmatite minerals, with larger resources in the U.S., Canada, Australia, China, Zimbabwe, and Russia. Lithium possesses a unique chemical profile making it the lightest metal in the periodic table and the least dense solid element. Its atomic number is 3 (right behind helium at 2 and hydrogen at 1), and its density is just 0.53 kg/L. This alkali metal is probably best-known for its wide use in lithium batteries common in all sorts of electronics devices. Other industrial applications include manufacturing heat-resistant glass and ceramics, high-performance alloys used in aircraft, and lubricating greases. Lithium deuteride is used in staged thermonuclear weapons as a fusion fuel. Compounds of lithium are also used as mood stabilizing drugs in psychiatry. The breakdown of the global end-use lithium markets is estimated as follows: ceramics and glass, 31%; batteries, 23%; lubricating greases, 9%; air treatment, 6%; primary aluminum production, 6%; continuous casting, 4%; rubber and thermoplastics, 4%; pharmaceuticals, 2%; and other uses, 15%.