Fiorite
Encyclopedia
Fiorite is a hydrated silica rock, a form of opal
, found in cavities in volcanic tuff
. It has a pearly lustre and forms botryoidal
masses. It was named after Fiora
, Ischia
, in Italy
.
Opal
Opal is an amorphous form of silica related to quartz, a mineraloid form, not a mineral. 3% to 21% of the total weight is water, but the content is usually between 6% to 10%. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most...
, found in cavities in volcanic tuff
Tuff
Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...
. It has a pearly lustre and forms botryoidal
Botryoidal
A botryoidal texture or mineral habit is one in which the mineral has a globular external form resembling a bunch of grapes as derived from the Greek. This is a common form for many minerals particularly hematite where it is the classically recognized shape. It is also a common form of goethite,...
masses. It was named after Fiora
Fiora
The Fiora is a river in northern Lazio and southern Tuscany, which springs from the southern flank of the Monte Amiata, near Santa Fiora. After crossing the Lazio Maremma, it flows in the north-western part of the province of Viterbo before getting into the Tyrrhenian Sea near Montalto di Castro....
, Ischia
Ischia
Ischia is a volcanic island in the Tyrrhenian Sea. It lies at the northern end of the Gulf of Naples, about 30 km from the city of Naples. It is the largest of the Phlegrean Islands. Roughly trapezoidal in shape, it measures around 10 km east to west and 7 km north to south and has...
, in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
.