Hi, for non water soluble minerals you can use water displacement and a scale. Here are the steps:
Grab a cup or beaker and weigh it (write down its weight).
Fill it with water and note the water level.
Now weigh the mineral specimen and write down its weight.
Pop the mineral in to the cup and note the new water level.
Remove the mineral and the water from the cup and then fill the beaker with the same amount of water that the mineral displaced and weigh it again.
Now you just need to do the math...
Subtract the weight of the empty cup from the weight of the cup with the displaced water. This is the weight of the water that has the same volume as the mineral.
Next divide the weight of the mineral by the weight of the water and this will give the specific gravity of the mineral.
As an example, if the empty cup weighs 100 g, the mineral weighs 50 g, and the cup with the displaced water weighs 120 g, then the weight of the water is 120 g - 100 g = 20 g.
Therefore the specific gravity of the mineral is 50 g / 20 g = 2.5. You can record your measurements in crystal guide pocket edition under my specimen notes if you might need them again later.
