If you are good with it you can just tell by feel. Or you can tell by looks.
find out how many grams are in like a milliliter or something then measure
Several ways. If you know the material, calculate its volume using a beaker and water. Then use its known density to calculate the mass.
Well you can find them at ebay.com or craigs list
To measure weight, the instrument used must measure the force of an object directed into some direction (often against a near by heavy astronomical object, such as the earth, but it is also possible...
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