Notice of Minerals from New Holland. 161 
being usually of nearly the same size. Color, pure white ; lustre 
of P, pearly; secondary planes a, f, vitreous ; but the faces M, T 
possess a dull, waxy, or opalescent lustre, which I have not before 
observed in the crystals of this mineral, apparently, however, con- 
fined to the surface; and the same faces are more or less curved 
or hollowed, so as not to admit of measurement by the goniome- 
ter. Some of these faces form a regular uniform curve, inclining 
equally towards the terminal planes P, obliterating the small re- 
placements a, f, which are usually very distinct. 
Stilbite. (Prismatoidal Kouphone-spar, M. )—The crystals’ 
generally are not well defined, the masses consisting of pure 
white pearly folia, forming sheats or fasciculated groups, showing 
at their free extremities, only imperfect crystalline faces of a low 
pyramid, inclining from the solid angles of the prism. Some of 
these masses, composed entirely of the stilbite, are of a globular 
form, presenting on fracture, a radiation of fibres from a common 
centre. A few small, but very brilliant, and perfectly transpa- 
rent crystals of this mineral, were however seen in some of the 
vesicular cavities of the amygdaloid, exhibiting the pri- 
mary prism, compressed into low six-sided tables, the 1) 
four replacements at the summits of the prism being [s 
narrowed down so as to form regular beveled edges upon 
the four corresponding sides of the tables, producing a 
form nearly similar to Fig. 6, taken from the System of \\ 
Mineralogy by Beudant, Vol. 2d, plate x, fig. 62. 
Mesotype of Phillips. GDesiiesicns Kouphone-spar of Haidin- 
ger.)—A nest of the crystals of this mineral was met with in the 
form of small implanted individuals, occupying the cavity of a 
mass of quartz and chalcedony. They are in rhombic 
prisms, colorless, transparent, and of a glassy lustre; but a few 
of them have a silly, fibrous appearance, similar to some of the 
specimens met with in the more ancient lavas of Vesuvius. They 
‘do not form groups of united, divergent crystals. 
- Rhombohedral Quartz.—I was so fortunate as to find 
this collection, besides several of the sub-species of this mineral, 
two or three specimens exhibiting the primary obtuse rhombeid 
in great perfection, and of considerable size ; some of them mea- 
suring half an inch across their planes. - They present highly 
po surfaces, are transparent and we and it is evident, 
Vol. xxx1x, No. 1 —April-June, 1840. 
Fig. 6. 
