Mineralogy and Geology. 427 
Prof. Guyot. The results of my researches appeared in March, 1859, in# 
a memoir upon Euphotides, in the American Journal of Science, fhe ~ 
xxvii, p. 336. I there showed that the jade, which forms the base of 
It has a density of 3-33-3:38, a hardness equal to quartz, and is only 
attacked by acids after being heated to whiteness. This mineral is always 
compact, tough, with a somewhat gy "ast fracture. Its color is whitish, 
with shades of green, blue or red. It sometimes encloses lamelle of a 
triclinic feldspar, which ’ Lreprscaa by oie and resembles labradorite ; 
its presence serves to explain the error of those who have sagen this 
e saussu 
8 
actinolite. The smaragdite of the euphotide is a grass-green pyroxen 
sometimes mixed with ornblende, and yielding, by analysis, chrome, 
nickel, and traces of cobalt.” 
e analyses of two specimens of the jade from the euphotide of 
ite fons (density 3°33 and 3°38) showed it to be a silicate of alumina 
and lime, with two or three hundredths of.soda, giving for the oxygen 
ratios of the silica, pais, and protoxyd, nearly 3:2:1, whi ch are 
related to the family of the garnets, epidotes ~~ ie aba I therefore 
referred it to this last species, the jade of De Sauss 
the memoir from which the foregoing settle are cited, I insisted 
upon the relation of isomerism, or rather of polymerism, which exists 
(Comptes Rendus, 1855, xli, 79). The different rhombohedral carbon- 
8) yanite and sliuntibh hornblende and pyroxene, offer in like 
mples of 
bake same time each one of these cacbohates: ae silicates 
belongs an another possible series, the terms of which differ by nM,0,, 
corresponding to more or less basic salts.” 
“ Meionite, with the ratios 3:2:1, is the most basic term known 2s 
the series of the wernerites. The e proportion of silica in these m 
augments until we find in dipyre the ratios 6: 2:1, with density which 
does not exceed 2°66. We might then expect io find a silicate which 
should be to dipyre, sees ee or saussurite is to meionite, and Mr. 
ur has recently had th fortune to meet with such a mineral in. 
a specimen of jade from China, of which be has ap given the deserip- 
tion ely fhe analysis (Comptes oe oh 4, This substance 
our. Sc1.—Seconp SeriEs, VoL. XXXVI, N Tae hee v., 1863, 
55 
