700 SCIENTIFIC RECORD FOR 1885. 



The chloride of sodium (or potassium) shown in the analyses is prob- 

 ably present as impurity. Excluding this the composition becomes: 

 4Na2S04 + NaaCOa, which requii es ^82804 84-27, NazCL'a 15-73 = 100. 



Mydrogiobertite (Idrogiobertite). — As the name indicates (from ^udivp, 

 water, and giobertite, a synonym of magnesite), this is a new hydrous 

 carbonate of magnesium ; it is from Vesuvius, and is described by Eu- 

 genio Scacchi. The mineral was fomid in the interior of a mass of 

 augitophyre, in the neighborhood of Pollena. It appears in spherical 

 forms from 2 to 15 millimeters in diameter. These have a comi^act tex- 

 ture and a light gray color. The specific gravity varies from 2-149— 

 2-174. Small crystals of magnetite are imbedded in the spheres, both in 

 the surface and in the mass. Two analyses were made, with the follow- 

 ing results : 



Both analyses have been calculated to 100, after deducting the small 

 amount of impurity present (magnetite, &c.). They correspond closely 

 to the formula Mg2C04 + 3aq, which requires: CO2 24-72, MgO 44-94, 

 £120 30-34=100. The nearest related minerals are hydro-magnesite 

 (Mg4C30io-+-4aq) and the doubtful lancasterite. 



L&venite (or Lovenite). — This new mineral, also announced by W. C. 

 Brogger, is like cappelenite (above), from an island in the Langesunds 

 fjord, Norway. It is found in prismatic crystals belonging to the 

 monocliuic system. The axial ratio deduced is, « : /^ : c : = 1-0811 : 1 : 

 0-8133, and the obliquity /J = 71° 24i' ; the form, consequently, is some- 

 what related to that of pyroxene. The cleavage is perfect parallel to 

 the orthopinacoid. The optic axes lie in the j)lane of symmetry, the 

 acute bisectrix beiug inclined forward about 204° to the vertical axis. 

 The color is chestnut-brown to yellowish, with marked pleochroism. 

 The specific gravity is 3-51. An analysis by P. T. Cleve gave : 



Si02 Zr02 re2O3(0 MnO CaO NaiO ign. 



33-71 31-65 5-64 506 11-00 11-32 1-03 = 99-41 



It is somewhat related in composition to the hexagonal catapleiite, 

 but contains less silica. 



Pinnoite. — Described by H. Staute as anew magnesium borate. It is 

 l^robably to be regarded only as a decomposition product of boracite. 

 It occurs at Stassfurt intimately associated with white earthy boracite. 

 It has an even fracture with a glistening surface, and sometimes shows 

 traces of a fibrous structure ; magnified slightly it appears fine-granular 

 to compact, with occasional crystalline planes. The color is sulphur- 

 yellow to straw-yellow, sometimes pistache-green ; also at times it has a 

 grayish or reddish tinge. The hardness is 3 to 4; the specific gravity 

 2-27. The mean of several analyses by Staute and Stromeyer gave: 



B2O3 MgO H2O Fe CI 



[42-50J 24-45 32-85 015 0-18 



