200 Notes on “ Inclusions” in Gems, &e. By Isaae Lea. 
“at the time of its assuming the solid state, the solution endured a 
high temperature.” 
Calcite has been found to contain nearly a quart of this fluid,* 
but it is not as common to be found in small cavities as it is in 
quartz. 
Fluorite.—Cavities in this mineral are rarely found, but they 
are sometimes seen with fluid and air-bubbles. 
Apatite.—I have never observed cavities in this mineral, but I 
have not given it much attention in microscopic examinations. 
Feldspar Growp.—In a former papert I gave the result of the 
examination of many specimens of various species. Since then I 
have examined numerous specimens of Labradorite, and found no 
cavities, but the black crystals were very numerous. In the moon- 
stone of this country I have not observed cavities or crystals; but 
in two specimens, out of about one hundred from Ceylon, I have 
seen a series of very regular quadrate cavities or crystals which do 
not appear to have any fluid. 
Tourmaline-—This interesting mineral is found beautifully 
crystallized, and of almost all colours, white, brown, green, red, 
black, &c. The finest are found at Mount Mica, near Paris, 
Maine.t Some of these specimens have small internal elongate 
crystals, which are terminated. A red specimen (Rubellite) in my 
collection has many irregular cavities. One green one from Ceylon 
has cavities with fluid, and another has very minute black acicular 
crystals in one direction. In brown crystals from Lower Dianburg, 
Carinthia, there are rough objects in the interior, evidently another 
mineral enclosed, which do not require the microscope to detect 
them. 
Cyanite.—Of the white and the blue varieties I have not ob- 
served any well-defined cavities or crystals; but in the grey-bladed 
cyanite, found at Cope’s Mills, near West Chester, Pennsylvania, 
there are always, I believe, small black masses which do not take 
a regular form, but are usually elongate. These may easily be 
detected by splitting a crystal along its eminent cleavage, and 
examining the cleavage face with a lens of small power; but a 
higher power is preferable. 
Quartz takes upon itself many colours. In it are found cavities 
in very great numbers, particularly in the clear fine crystals. 
Those which exist in such an abundance in Herkimer County, New 
York, and which are so limpid, and finely and doubly terminated, 
are sometimes furnished with thousands of cavities, even in small 
specimens, and these are of many various forms, frequently con- 
* Specimen in the collection of the late Dr. Chilton, of New York. 
+ ‘Proc. Acad. Nat. Sci.’ May 11, 1869. 
} Dr. Hamlin has published a beautiful little work on the Tourmaline, with 
illustrations, 
