50 Dr. Mead’s Localities of Minerals. 
chusetts, 1 had an opportunity of examining the Mineral- 
ogy of some districts which have hitherto escaped notice. 
If the observations which I have drawn up on this: subject 
are sufficiently interesting to deserve a place in your Jour- 
nal, they are much at your service. 
ours very respectfully, 
MEADE. 
Pror. SInuiman. 
On visiting Worcester, Massachusetts, I met with a Spe- 
cimen in the Cabinet of William Lincoln, jun. Esq. which 
attracted my notice. This promising Mineralogist was po- 
lite enough to accompany me to the place where it was ob- 
tained, and where | procured sufficient to ascertain that it 
was Vesuvian or Idocrase of Haiiy. The Character of it 
is as follows. 
t occurs in Groupes and in Cavities, seldom imbedded, 
massive or crystalized; form, a short rectangular four sided 
Prism, more or less truncated on the lateral edges so that 
some of the crystals are distinctly eight sided. The ter- 
deeply striated so as to resemble the Egerine of Werner. 
Colour brown, lustre brilliant, translucid, some of the 
crystals are imperfectly transparent, about the hardness of 
quartz, easily fusible with intumescence into a transparent 
glass. It is accompanied by small pale green crystals of py- 
roxene, and beautiful smal] garnets of a wine yellow colour, 
crystalized in rhomboidal dodecahedrons. The matrix of 
all these appears to be a compound rock containing a mix- 
ture of massive Garnet,Pyroxene, and Idocrase. The Cay- 
ities are lined with Calcareous Spar in which the crystals of 
Idocrase of about one fourth of an inch in length appear to 
be set; by submitting the Carbonate of Lime to the action 
of dilute Nitric acid, beautiful and distinct Crystals of Ido- 
crase and of Garnet can be obtained. 
cavities and leaves the crystals unaltered; this is very 
much the case with respect to other minerals particularly 
