While comparing Oligoclase and Feldspar physical properties, the important data you should know is its chemical composition. Since chemical formula defines the molecular structure of the crystal, most of the physical properties like color, tenacity, solubility are governed by Oligoclase and Feldspar chemical formula.
Another important criteria for qualitative analysis of gemstones is Oligoclase and Feldspar Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Oligoclase and Feldspar Optical Properties during the identification of gemstone. Specific gravity of Oligoclase is 2.56-2.75 whereas that of Feldspar is 2.56-2.75.