SALOON. 
Nat. Hist. 
" 18 
a substance generally referred to the natural order 
of quartz, but with whose history we are but little 
acquainted. 
(Case 6.) Besides some specimens of sub¬ 
stances related to common quartz, such as the 
avanturino quartz, the flexible sandstone from 
Brasil, and the iron-flint (a substance in which 
oxide of iron exists in chemical union with silica) 
this case contains varieties of the stalagmitical 
quartz, also called quartz sinter. The most re¬ 
markable among these are the siliceous concre¬ 
tions deposited by the celebrated hot spring ill 
Iceland, the Geyser, and which are distinguish¬ 
ed into siliceous tuf, and calcedonic sinter. An¬ 
other variety of it is the pearl-sinter from Santa 
Fiora in Tuscany (whence it obtained the name 
of Fiorite), and from the island of Ischia. To 
this may also be referred the ceraunian sinter, or 
those enigmatical siliceous tubes, which were 
first found in the sands of the Senner heath, in 
the county of Lippe, (where, from their sup¬ 
posed origin, they are called lightning tubes), 
and subsequently, under similar circumstances, 
at Drigg, on the coast of Cumberland, which is 
the locality of the specimen here deposited.—The 
hyalite is placed here, as a mineral related both to 
stalagmitical quartz and calcedony.—The rest of 
this glass case and the greater part of the follow¬ 
ing* 
