They begin green and change colour as they ripen, from green to light brown to red or purple to midnight black.
While green olives are the most commonly used for pressing into oil, some commercial producers utilise a blend of green and black.
Fossils indicate that olive trees evolved between 20 million and 40 million years ago.
The average lifespan of an olive tree is between 300 and 600 years.
Olive trees do not yield olives until they are approximately 5 or 6 years old.
Olive branches have historically been used to represent honour.
There are more than 1,000 varieties of olives.