|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
The carat (ct) is a unit of mass equal to 200 mg (0.2 g; 0.007055 oz) and is used for measuring gemstones and pearls.
A grain is a unit of measurement of mass, and, for the troy grain, equal to exactly 64.79891 milligrams. It is nominally based upon the mass of a single seed of a cereal.