The Terpene available in nature is colourless and transparent. But often it has been observed that it contains some impure substances which impart a yellow colour to it. The boiling point of the Terpene is its other physical quality to identify it. The boiling point depends on the carbon chain length. It is also very light and less viscous than vegetable oils. it is slightly volatile. and slightly more soluble in water than in Nonpolar Solvents. a particular type of aroma is associated with every kind of Terpene.