Resins may be identified based on their physical and chemical properties. In addition, they may be identified by individual chemical tests to detect the presence of specific chemical constituents.

1. Throw a small piece of resin in water. Resins being heavier than water sink in it.
2. Take a few fragments of the resin in a spatula and show it in the flame. Resins soften, fuse, and melt giving a sticky liquid. On further heating, they burn with a smoky flame.
3. Test of solubility: Treat a piece of the resin with water and heat. It does not dissolve. However, they dissolve in most organic solvents such as alcohol, ether, chloroform, and acetone.
4. Balsams rich in acids turn blue litmus red.
5. When solutions of the resin in ether or acetone are evaporated on a glass slide, they leave a thin film. Oleo gum resins like myrrh change colour to violet when the film is exposed to fumes of nitric acid or bromine.
6. Test for colophony:
   1. Dissolve a small quantity of the powdered resin in 5 ml acetic anhydride. Add one drop of sulphuric acid. Formation of purple colour changing to violet indicates the presence of colophony.
   2. To 1 ml of a solution of the powdered resin in petroleum ether add 2 ml of copper acetate solution. Formation of an emerald green colour in the organic layer confirms the presence of colophony.
7. Balsams may be identified by the presence of crystals of cinnamic acid. When a small piece of the drug is warmed and pressed into a thin film between two glass slides, on cooling, crystals of cinnamic acid may be seen embedded in a transparent mass when viewed under a microscope.
8. Test for cinnamic acid containing resins: When a little of the crushed resin is warmed with dilute sulphuric acid and potassium permanganate, fumes of benzaldehyde emanating, indicate the presence of resins such as benzoin, balsam of tolu, and balsam of peru.
9. Test for guaiacum resin: Dissolve a small portion of the resin in alcohol and add a drop of 2% solution of ferric chloride. Due to the presence of Guaiaconic acid the solution attains a blue colour. This test is also answered by male fern resin and balsams, which give a light green colour changing to brown.
10. Test for umbelliferone: An alcoholic solution of Galbanum resin gives a brilliant blue fluorescence when poured into an alcoholic solution of ammonia, as it contains free umbelliferone. Asafetida (0.5 g) gives this test (as umbelliferone is formed form ferulic acid and resorcinol) when it is boiled with 5 ml concentrated hydrochloric acid and 5 ml water. The cooled filtrate is to be treated with an equal volume of alcohol and twice the volume of ammonia.