18 
SALOON. 
Nat. Hist. 
Case 6. Besides some specimens of substances 
related to common quartz, such as the avantu- 
rino 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 remarkable 
among these are the siliceous concretions depo¬ 
sited by the celebrated hot spring in Iceland, 
the Geyser, one variety of which is called silU 
ceous tifl the other calcedonic sinter. Another 
variety of it is the sinter from Santa Fiora 
in Tuscany (whence it has 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, 
from which name those of fulgurite, ceraunian 
sinter, astraphyalite, are derived), and subse¬ 
quently, under similar circumstances, at Drigg, 
on the coast of Cumberland [see British Coll.], 
near Konigsberg, at Halle on the Saale, and 
latterly near Dibbla in the Tuarick country, 
Africa, which is the locality of the specimens 
here deposited.—The hyalite is placed here, as a 
mineral related both to stalagmitical quartz and 
calcedony.—The rest of this table-case and the 
greater part of the following are occupied by 
calcedonic substances. Among the specimens 
of 
