Dulcote Agate 120.71 ct
Oval Cabochon 64.50 x 37.30 x 6.40 mm
w721

Dulcote Quarry, near Wells, Somerset, UK

The agates from Dulcote Quarry in the Mendip Hills are some of the finest in Britain but are no longer being
obtained since the quarry was closed many years ago.
They occurred as nodules in the red marly clays overlying the Carboniferous Limestone. These clays were laid
down in an arid, tidal-flat environment during the Triassic period (200 million years ago) when Britain was situated in
the tropics.
How these nodules were formed has been the subject of debate but it is thought that they were originally composed
of anhydrite, which was slowly replaced with quartz from the outside inwards, with varying amounts of hematite and
other minerals creating colour banding. Some nodules are hollow and contain crystals of quartz.