Convert from obolos [Ancient Greece] to gin [China]

Unit Definition (obolos [Ancient Greece])
The obolos [Ancient Greece] is a historic unit of weight or mass. The obol is a very small weight that originated as the weight of a tiny Greek coin. In ancient Greece the obolos was equal to 1/6 drachma, or roughly half a gram (8 grains).

Unit Definition (gin [China])
The Chinese weight unit also called the catty.