Not all gemstones are classified as minerals. Most gemstones contain inorganic compounds, but the most beautiful and sought after members are organic gemstones.

The main features of organic gemstones:
1. You should consider organic gemstone as a gemstone.
 There are some stones which are not considered as gems but still they are widely used in jewelry.

2. Organic gemstones should include compounds which were originally living tissue. Amber belongs to the organic compounds.

3. Organic compounds of these gemstones are the most complex in nature. Organic chemistry is considered as one of the most difficult sciences by the most students.

4. There are two major groups of the organic gemstones: fossilized and contemporary.

a) Fossilized organic gemstones
These stones were made of once living tissue. Over the period of time natural forces have turned them into the present gem quality form.

Amber is a fossilized organic gemstone. It has been formed from the tree sap which has been fossilized over thousands or millions of years.

The clear amber should carry a yellowish color. Its name derives from ambergris, the secretion which has a sweet smell of the sperm whale once used in perfume making.

The most collectable examples of amber are those that include perfectly preserved insects.

Another example of fossilized organic gemstones is Jet.
Jet which can be also called lignite is a type of coal. It is formed from ancient deposits of decaying wood under extreme pressure.

Soft jet is a kind of jet which has been formed in fresh water.  Salt water is an environment for the formation of hard jet. Like coal jet is a shiny black stone. The famous English phrase 'jet black' comes from this organic gem stone.

Ammonite is another fossilized organic gemstone.
It is formed from the fossilized remains of ancient sea anemones. Its appearance is similar to the opal and its surface can be cracked or mottled. Due to the cracked surface it can have a look of 'dragon scales' or a stained glass window.