150 Dr Anderson’s Account of New Mineral Species. 
Leucophane. It is a silicate and titanate of the oxides of cerium 
and lantanium. It is in part crystallized in imperfectly- 
formed prisms, and in part amorphous. It has one evident, 
and several obscure cleavages. The first of the two varieties 
has a lustre between resinous and vitreous ; the latter is resi- 
nous. Colour dark reddish-brown, in thin plates, red by trans- 
mitted light. Gives a greyish-brown powder, has the hard- 
ness of fluor-spar, and sp. gr. from 2.93 to 2.98. Before the 
blowpipe yields much water, and by ignition becomes brownish~ 
yellow ; melts easily into a brownish-green pearl ; with borax 
gives an amethyst-coloured glass, which in the reducing flame 
becomes nearly colourless ; does not fuse so easily with micro- 
cosmic salt, and in the reducing flame gives the colour of oxide 
of titanium. As yet it has been only quantatively analyzed, 
and found to contain silica, titanic acid, oxide of lantanium, 
manganese, lime, a little magnesia, alkali, and water. The 
four first are the chief ingredients. 
Praseolithe.-—Discovered by Pastor Esmark, and described 
by Erdman. It is found at Briikke, near Brevig, in Norway, 
in granite, accompanied by chlorite, titaniferous iron, and tour- 
maline. It is irregularly crystallized, and seems to form four- 
sided prisms, which, however, are often got with six, eight, or 
twelve sides, with the angles and edges rounded off. Colour 
green, from light to dark green. It has only one cleavage ; 
fracture splintery and conchoidal; lustre small; hardness be- 
tween cale-spar to fluor-spar ; gives a light green powder ; sp. 
gr. 2.754. Before the blowpipe gives water, and melts with 
difficulty on the sides to a bluish-grey glass. Its composition is 
Silicic acid, : F 2 40.94 
Alumina, ; : : -9 219 
Protox. of iron, : : 5 6.96 
— -—mangan., : . . 0.32 
Magnesia, . : 3 . 13.73 
Water, . ‘é : : : 7.38 
Oxides of lead, copper, cobalt, and lime, 0.50 
Titanic acid, R ‘ 0.40 
99.02 
Rosite.—This is the name given by Swanberg to a new mi- 
