17 
ment, begin the substances belonging to the spe¬ 
cies of quartz.— Rock crystal: various modifica¬ 
tions of its crystalline forms: small dodecahe¬ 
dral and other crystals,known by the trivial names 
of Gibraltar diamonds, Bristol diamonds, &c.; 
varieties of colour according to which the crystals 
obtain the vulgar denominations of smoky topaz 
or morion, cairngorm, citrine, &c.; specimens 
of rock crystal, inclosing various substances, 
such as rutile, brown iron-stone, micaceous iron, 
needle antimony, actinote, asbest, chlorite, &c. 
groups of rock crystal.— Amethyst quartz of 
various tints, in grouped crystals ; nodule lined 
with crystals of amethyst and cross-stone or 
harmotome, from Oberstein, &c. 
Case 5. Common quartz: among the specimens 
of this widely diffused substance, which offers such 
great variety in its external aspect, the more 
remarkable are those of hacked, corroded and 
cellular quartz from Schemnitz, as also the pseu- 
domorphous orsupposititious crystals, principally 
derived from modifications of calcareous andfluor 
spars; and, with regard to colour, the red quartz 
crystals from Compostella, imbedded in gypsum, 
and known by the name of hyacinths of Compos¬ 
tella; the blue quartz or si derite from Salzburg. 
■—Among the other varieties of quartz is the rose 
or milk quartz , which occurs only massive, and 
the prase , which appears to be an intimate mix¬ 
ture of common quartz and actinote.— Fibrous 
quartz .—In this table-case, are also deposited 
c some 
SALOON. 
Nat. Hist 
