250 The American Naturalist. [March, 



(CuO = 63.7 ; Cu Cl 2 = 13.5 ; H,0 = 22.8) leads to the formula 

 8[Cu(HO) 2 ]CuCl 2 + 4H 2 0. The name chosen for them is Footeite, 



after their discoverer. Rumpfite.— On the clefts of pinolite, from 



Jassing, in Obersteiermark, Germany, Firtsch 1 found associated with 

 talc a flaky, greenish-white, translucent mineral with a hardness of 

 1.5 and a density of 2.675. Under the microscope it appears to be 

 uniaxial and hexagonal. Its composition is : 



corresponding to H 28 Mg T Al 16 Si 10 O 65 . It deports itself like a chlor- 

 ite. Bolle'de.— Mallard and Cumenge 2 have found among the cop- 

 per series of Boleo, near Santa Rosalie, in Lower California, a large 

 quantity of a blue copper mineral that often crystallizes in cubes and 

 oetohedrons. It is associated with anglesite, cerussite, atacamite and 

 gypsum. An analysis of the cubical forms gave: 



Ag Cu Pb CI Aq 0(bydiff.) 



8.80 14.22 49.10 19.48 4.38 4.02, 



corresponding to Pb Cl 2 + CuO H 2 + J Ag CI or 3[Pb Cl(HO). 

 Cu Cl(HO)] -f- Ag CI. The hardness of the crystals is but little 

 superior to that of calcite. Their density = 5.08 and their index of 

 rafraction is about 2.07. Sometimes the cubes are modified by the 

 dodecahedron, but the dodecahedral faces have not their usual posi- 

 tions, that one most steeply inclined to each axis occurring nearer the 

 termination of that axis than the one less steeply inclined thereto, so 

 that the edges of the cube are replaced by pairs of two faces making 

 re-entering angles with each other. The optical properties of thin 

 sections of these crystals indicate that they are tetragonal, negative 

 forms that unite to give rise to a pseudo-regular one. The octahedral 

 crystals are in reality tetragonal pyramids with a : c = 1 : .9873. 



Boleite differs from percylite in containing silver. Sjogren 3 



describes three new minerals from Sweden. The first, astochite, occurs 

 as a coarse, columnar aggregate of a blue or grayish violet color at 

 Langban. Its cleavage is that of hornblende. Its density varies 



P . 31. 



