Rock of the Month
BOBONONG AREA, CENTRAL DISTRICT, BOTSWANA
“Botswana agate” is a banded agate (translucent chalcedony or cryptocrystalline quartz). It is distinguished by asymmetrical concentric banding and is mined in the Bobonong area of Botswana. The agate was formed in amygdules (gas cavities) in Baltic lava flows that were extruded at the top of the Karoo Sequence in the Middle Jurassic epoch 180 million years ago, in connection with the initial rifting phase of the break-up of Gondwana.
“Botswana agate” was a staple of the agate market in the 1960’s and 70’s but has become harder to find in recent years.
Updated March 2, 2016