LVIII.
LUMACHELLA.
If this
substance was known to the ancients, the name which they gave it is
unknown to us ; but we aie led to believe that it is a recent discovery.
The opaline lumachella comes from Corinthia, where it is found in a mountain called Pleybourg.
There,
under a ridge of lead minerals, is found a grey-brown marble which
contains many fossil shells of the primitive period, which are now
extinct. They are seldom found unbroken, and this will not appear
strange when we consider through how many terrestrial revolutions they
must have passed before being deposited amongst the substances which,
together with them, form the lumachella.
Some of these shells, brought to light by the help of the saw and polish, present all the colours of the rainbow.
Art
adds much to the natural effect of the lumachella, and then it clearly
shows most vivid waterings of a golden red, and emerald-green colour.