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 + NaaCOs, which requires Na2S04 84-27, NazCC'a 15-73 = 100. 



Eydrogiobertite (Idrogiobertite). — As the name indicates (from hjdwp, 

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

 carbonate of magnesium ; it is from A^esuvius, and is described by Eu- 

 genio Scacchi. The mineral was found 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 compact 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 : 



CO2 MgO H2O 

 2516 44-91 29-93=100 

 25-29 44-28 30-43=100 



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: CO3 24-72, MgO 44-94, 

 H2O 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 Laugesunds 

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

 monoclinic system. The axial ratio deduced is, a : b : c : = 1-0811 : 1 : 

 0-8133, and the obliquity /? = 71° 24J' ; 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 plane of symmetry, the 

 acute bisectrix being inclined forward about 20^° 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 : 



It is somewhat related in composition to the hexagonal catapleiite, 

 but contains less silica. 



Finnoite. — Described by H. Staute as a new magnesium borate. It is 

 probablj" 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 3285 0-15 0-18 



