About Specific Gravity Lab
Specific Gravity is defined as the the ratio of the density of a substance to the density of a standard, g water for a liquid or solid, and air for a gas (Webster). From specific gravity one can determine whether a soil is lighter than soil (specific gravity less than one) as a result making it float. Typical values for soils are in the range of 2.65 – 2.8. Organic soils, such as in our case, will often be below this range (and may even fall below 1.0) and soils with high levels of iron can go above 3.5.
Summary of collected raw data
compiled data with supporting sample calculations
VALIDITY of results
As mentioned above in our introduction, most specific gravity range from 2.65-2.8. These values are accurate for your typical soils such as clay and fine sands. This however is not the case with our "peat" soil. Table 1 below shows characteristics of peat. As it can be seen the typical specific gravity for peat usually ranges from .94-1.34. Our value of .94 is right at the lower threshold for peat specific gravity. These results fall right where we expect them. Since peat is full of organic material, it is very buoyant and will produce a very low specific gravity, since it is so light.