In addition to the well known beach pebbles, which can contain Jasper and agate, there are also primary occurrences of agate on this greek island. The finding-locations are a little further in the interior of the island and are difficult to reach for tourists.
In addition to agates that occur in more low-silica intermediate basalt as fillings of bubbles in the basalt ( amygdaloites -1, 3 ) also lithophysae agates (Thundereggs) in silica-rich volcanites can be found too. The thundereggs can reach sizes up to 20 cm diameter. The agates inside are often formed botroidal and are showing a rather weak banding and white to bluish hues.
There are also occurrences of petrified wood, which may also contain agate in cracks and cavities on the island of Lesbos.
In the year 2014 Michael Samouhus found a new locality for lithophysae with a high proportion of agate in Polichnitos(6, 7, 8, 9, 10, 11, 12, 13).. These agates often show a large proportion of gravitational formed agate, so-called "water level-agate". Also strange spherical inclusions-maybe pseudomorpho - can be found in the center of the lithophysae.