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.