Convert from grano, grani [Italy] to petagram

Unit Definition (grano, grani [Italy])
The grano, grani [Italy] is a traditional Italian weight unit, varying in size but typically about 50 milligrams. The plural is grani.

Unit Definition (petagram)
The petagram is a metric unit of mass equal to 10E15 grams or 1 gigatonne (one billion metric tons). This unit is used in atmospheric science and other scientific contexts where large masses are considered.