Dollar gold to silver ratio be exactly 15.5. Then a pennyweight of gold, that is 24 grains of gold, is nearly equal in value to a dollar of silver (1 dwt of gold = $1.002 of silver). Second, a dollar of gold is nearly equal in value to a pound of silver ($1 of gold = 5754 3/8 grains of silver = 0.999 Lb of silver). Third, the number of grains in a dollar (371.25) roughly equals the number of grams in a troy pound (373.24). The actual process of defining the US silver dollar had nothing to do with any
Presolar grains range of micrometers. Presolar grains consisting of the following minerals have so far been identified: The study of presolar grains provides information about nucleosynthesis and stellar evolution. Grains bearing the isotopic signature of "r-process" (rapid neutron capture) and alpha process (alpha capture) types of nucleosynthesis are useful in testing models of supernovae explosions. For example, some presolar grains (supernova grains) have very large excesses of calcium-44, a stable isotope of calcium which normally composes only 2% of the calcium abundance. The calcium in some presolar grains is composed primarily of Ca-44, which is presumably the remains of the extinct radionuclide