It is rare for any mineral to show more patterns created by nature than Agate. In reality Agate is Chalecedony Quartz (SiO2) that forms in concentric layers about some common centre. Each individual Agate forms by filling a cavity in host rock. As a result, Agate is often found as round nodules, with concentric bands like the rings of a tree trunk.

Description: This is a sizeable specimen of the world-famous Horni Halze agate. The colouring is very striking consisting of dark-red and yellow swirls in a matrix of chalcedony quartz. The quartz contains metallic-looking inclusions which provide a very attractive contrast to the coloured bands. An excellent display specimen.

Location: Horni Halze, Czech Republic.