* Specific Gravity: This is the ratio of the density of a substance to the density of a reference substance, usually water.

* Floating: An object floats when it is less dense than the fluid it's in.

* Water's Specific Gravity: Water has a specific gravity of 1.

Since a specific gravity of 1.3 is greater than 1, it means the substance is denser than water. Therefore, it will sink.