Mineralogical Notices by Prof. Meneghini. 63 
Lustre vitreous; colorless to flesh-red and colophonite-red. Com- 
position ; 
Si Al Meg Na K i 
1, 59347 «=. 22083 = «10-250 0450 = 0015 = 7-650 99-795 
2 «58875-29083 10000 0-450 «0015 768899111, 
Oxygen ratio 1:3:8:2,like analcime. Formula, (Mg, Na, K)*Si2+ 
3A18i°-+6H= (supposing the protoxyds magnesia alone) Si 57-96, 
Al 2414, Mg 941, HW s22—9973. The formula 2h Sit + 541 Si? +10H 
would correspond to Si5s-43, ¥1 23:05, Mg 10-71, H.808=10027; but the 
preceding is to be preferred. Dissolves in the acids, and the solu- 
lion gives with potash a flocculent precipitate which moistened 
with nitrate of cobalt and heated, becomes of a blue color. Ina 
closed tube gives water. B. B. fuses with difficulty. Covers the 
interior of geodes in the Gabbro rosso, or the surfaces of contact 
between the Gabbro and the Ophiolite, sometimes having a me- 
Often accompanied with Calcite, Caporcianite 
and Picrothomsonite, ; 
Picrothomsonite-—T rimetric. Mass radiated in one direction, 
and in a direction normal to this laminated according to two 
cleavage directions equally easy parallel to Mand M. H.=5. 
G. = 2-278. Lustre pearly; white; transparent in small frag- 
ments; very fragile. Composition: 
Si Al Oa ise Nae SS 
40356 = 81-251 «10-998 G-265 «= 0285 ©=——-:10°790= 99-940 
Formula 2 (Ca, Mg)*Sit-541 Sit ott—Si 40-08, 41 31-83, Ca 10°55, Mg 7°58, 
1 1000=10004, Tt differs a little from that of Thomsonite, in hav- 
ing the ratio of the protoxyd and peroxyd silicates 2 : 5 instead 
of 2:6, and in the proportion of water also being a little smaller. 
Portite, (a new species dedicated to M. Porte, “qui a fait re- 
haitre Vart minéraire en Toscane”’).—Trimetric ; in radiated 
ho ee with cleavage very distinct parallel to the faces of a 
harg prism of about 120°. H=5. G=2-4. White; opaque; 
Ustre Vitreous, Composition :— 
6 a Mg Na kK i 
125 27500. 1-159 «4878 «= O16T 0-100 7917100481. 
Tym (Mg, Ga)*Si2-++41 Sit +7H=Si 5836, Al 25-95, Mg 7-71, Ht 7-95. 
consider it a magnesian harmotome; yet there is too large a differ- 
ence in the proportion of water, whieh, I believe, justifies giving 
a different name. Dissolves in acids even in the cold, and ge- 
es. The solution whit 
