• Firstly, a palynomorph must be within the size range of 5- 500 micrometres, no smaller (there are a few exceptions for larger samples).
• Anything made up of calcium carbonate (CaCO₃) is not a palynomorph.
• It is an organic compound (CHO), which is resistant to HCl (hydrochloric acid) and HF (hydrofluoric acid).
• Although able to resist those acids, it corrodes in strong oxidizing environments (as well as nitric acid and H2O2) or high-alkali surroundings (KOH).
• It thermally alters to darker colours due to loss of oxygen and hydrogen molecules - a process called carbonization.
• It has complex polymers.

• Sporopollenin
• Chitin
• Pseudochitin

        Sporopollenin is the most common of the three.  It is found in dinoflagellates, acritarchs, and the cell walls of spores and pollen.  It is very similar to chitin in behaviour and properties.  It is the most inert organic compound known.  Although it is the most common, scientist and experts are still uncertain of the chemical structure.

        Chitin is found in spores, fungi, scolecodonts, arthropod organs (insect mouoth parts), and microforams.  It is structurally very similar to cellulose, the only difference is the addition of the acetamide group (HNCOCH₃) - see diagram below.  Chitin is more resistant to carbonization than sporopollenin.