12 TRANSACTIONS OF THE [oct. 29, 
Implanted on the damourite taken out of the pockets con- 
taining herderite at Stoneham, Me., described by Mr. W. E. 
Hidden (Amer. Jour. Science, February, 1886), I noticed some 
small, flat crystals, less than one-fourth of an inch long. These, 
after having had for some time, I at last suspected to be ber- 
trandite, and through the kindness of Dr. 8. L. Penfield this 
conjecture has been verified. ‘They are especially interesting, 
because they show an entirely new crystalline development, 
being hemimorphic in the direction of the vertical axis, as in 
struvite and calamine, according to Dr. Penfield. This hemi- 
morphism explains also the curious rounded, one-sided develop- 
ment of the Mt. Antero crystals. The specific gravity is 2.591. 
Among a lot of Mt. Antero (Colorado) minerals recently sent 
me were a few crystals of bertrandite, of the largest size yet ob- 
tained, measuring 27mm. in length, and 6mm. in width. These 
were implanted on blue beryls, some over two inches long and 
three-fifths of an inch in diameter, curiously eaten out and 
often coated with bertrandite and phenacite; both these mine- 
rals evidently the result of the decomposition of the beryl. 
Some of the new prismatic phenacites in the same lot were the 
largest yet found, one measuring 26 mm. in width, and 20 mm. 
in length, doubly terminated with faces of the simple rhombo- 
hedron. The same locality yields beautiful orthoclase in simple 
Baveno and Carlsbad twins, in color and form identical with 
the finest crystals from Baveno, Italy, from one and one-half 
to two and one-half inches in length. ‘These specimens were 
obtained near the upper part of Mt. Antero, at an altitude above 
12,000 feet—a locality that is generally concealed by snow, and 
only accessible for a short time in the summer. 
From San Luis Park, Colorado, have been received some curi- 
ous amethyst crystals, light colored, very long, and with fluid- 
cavities arranged conformably to enclosed pyramidal planes, which 
thus appear, as in ‘‘ phantom crystals.” A succession of pyra- 
midal faces gives the great length, and is terminated trihedrally. 
Arizona has now afforded us, in addition to the remarkable 
azurite and malachite, some of the finest known crystals of 
cuprite. They are of two forms; the first are large cubes, mea- 
suring from 10 mm. to 25 mm. in width, occurring as group- 
