A. W. Jackson—Colemanite, a new Borate of Lime. 447 
as well as that from the quartzite bed at Santa Luzia, was in 
well nntawen doubly terminated crystals. 
Th of this region is excessively fine. A number of 
opaciaiene ye Sao Gongalo and Santa Luzia examined micro- 
scopically showed distinct crystalline grains, with sharp, well 
defined angles. Nothing of a leafy character or resembling 
the flakes on ee described in the prabdlink article were 
noticed. The grains range in size from 0°05 millimeters for 
single crystals a to 0°4 millimeters for agglomerations of sev- 
eral crystals, and present the same characters as those obtained 
by eeppiee: the arsenopyrite of the Morro Velho vein. 
a company has been sper 4 organized to reopen the 
Sio ‘Gonsae mines by the hydraulic method it is to be hoped 
that further details regarding this interesting se tebe may soon 
be obtainable. As already mentioned, a few small gold-bear- 
ing quartz veins occur, and in future abtinion under more 
favorable circumstances it may be possible to determine some- 
thing bearing on the question as to whether or not these veins 
have been enriched from the adjacent rock. 
Art. LV.— On ger aren a new Borate of Lime; by 
. WENDELL JACKSON. 
A NEW borate of lime has’ recently been determined by J. 
T. Evans, of the California Ppccngin of Sciences. His analysis 
fixes its formula as follow 
2CaO . 3B,03 . 5aq. 
It differs from pandermite in containing five instead of three 
molecules of water. Its main interest lies however in its 
morphological relations. Mr. Evans kindly sent me a crystal 
for investigation and subsequently I obtained from another 
source twenty other crystals. They are all small, colorless and 
in the main with faces in good condition. The examination in 
the polariscope showed that the erystals were monoclinic. The 
plane of the optical axes is normal to the clinopinacoid ea 
makes an angle of 83° 25’ with the chief axis (in front). 
ith a primitive form havin 
a:b: c=0°774843 : 1: 0540998 and B=69° 50! 45" 
IT have determined already the following forms: 
