Jet is an organic material that is closely related to coal
and is often worked as though it were a mineral.
It is mainly found in strata from the Lower Jurassic era,
originating from logs of ancient Araucaria trees (ancestors of the modern
‘monkey puzzle’) that fell and were washed out to sea, eventually being buried
under other sediment that, over millions of years of heat and pressure,
converted them into a relatively soft form of lignite or coal.
Pieces of jet are often found on beaches in such places as
Whitby in North Yorkshire, where they have fallen from nearby cliffs as a
result of local erosion.
The softness of jet allows it to be carved into many
different shapes. It can also be polished to a brilliant sheen, which has long
made it a popular material for use in jewellery.
Examples of jet jewellery have been found from Bronze Age
and Roman times. It underwent a revival in popularity during the late Victorian
era when people copied the fashion set by Queen Victoria for ‘mourning
jewellery’ after the death of Prince Albert (she never wore anything that
wasn’t black for the rest of her life).
© John Welford
No comments:
Post a Comment