As I don't know the source for any of the density values, it's hard to specify what the difference is due to. This could just be a refinement on the measurement such as improvements in purity, precision, or densification. The other possibility is that the measurements could have been carried out at different temperatures. The coefficient of thermal expansion for gold is 14.2ppm per degree C. Fifty degrees' difference would change the volume enough to account for the discrepancy. Chris On Friday, November 1, 2002, at 08:05 pm, Wayne Seguin wrote: > The Materials list for Material: Gold (Au), bulk shows a Density of > 19280 kg/m^3, but I've found many other references that claim the > Density is 19320 kg/m^3. (one example: > http://www.stanford.edu/~yueliang/constant.htm) > Does anyone know what the difference is between the two? (please don't > say 40kg). > Thanks > Wayne -- Christopher F. Blanford Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK Phone: +44 (0)1865 282603; Fax: +44 (0)1865 272690 PGP keyID: 8D830BC9 http://pgp.mit.edu/