The formula for specific gravity is:

where
is the density of the substance and
is the density of water.
The density of water,
= 
Substituting the values in above formula we get,


The formula of density is:

The density of mercury is 
The mass of mercury is 
Substituting the values in density formula:


Answer:
Salt, (Coal is a mineral but barely, but Salt is your best answer), (And if it's multiple choice its Salt and Coal)
Explanation:
Salt (NaCl), sodium chloride, mineral substance of great importance to human and animal health, as well as to industry. The mineral form halite, or rock salt, is sometimes called common salt to distinguish it from a class of chemical compounds called salts.
Insulation wraps because independent is the variable you are changing to affect the dependent variable (what you are measuring)