210 
POPULAR SCIENCE REVIEW. 
METALLURGY, MINERALOGY, AND MINING. 
Crystals of Fayalite from, a Furnace Cinder. — At one of the meetings 
of the Manchester Philosophical Society, Mr. William H. Johnson, B.Sc., 
showed two remarkable pieces of iron cinder from a furnace in which 
iron is re-heated. The samples showed on one side small dark prismatic 
crystals, which appeared to have been formed in a cavity of the cinder as it 
cooled in the cinder bogie. The reverse side of one of them had formed 
the wall of a second cavity; its surface was, however, smooth, black, 
shining, and studded all over with the sides of oblong jet-black crystals 
unusually iridescent. He remarked that probably these crystals were faya- 
lite, an iron chrysolite, a mineral found in the Mourne Mountains in Ireland, 
which is sometimes iridescent, and whose chemical composition is repre- 
sented by the formula Fe 2 Si0 4 . They are the more worthy of notice from 
the rare occurrence of crystals in mill-furnace cinder. 
Ludwigit, a New Mineral from Banat. — According to a paper by Herr G. 
Tschermak, in a late number of Liebig’s “ Annalen der Chemie,” specimens 
of this mineral have been recently brought from Morawitza. It consists of 
fine, generally parallel fibres, whence recent specimens have a silky lustre. 
The colour is blackish-green, but there is a modification almost black with 
a violet cast. It is very tough, and the fibres are not easily separated from 
each other. They are sometimes 8 centimetres in length. The mineral is 
accompanied by magnetite in the shape of small grains, which intersect the 
mass in threads and veins. Granules of calcite are also met with. In hard- 
ness the mineral is equal to apatite. Its sp. gr. ranges from 3 ‘907 to 4-016. 
The streak is blackish-green, but paler than the mass. The finest frag- 
ments, when examined under a power of 200 diameters, are transparent, 
with a greenish-brown colour. Its composition is — 
A new Mineral — Living stonite. — This mineral, recently described by Senor 
M. Barcena (see u Silliman’s American Journal,” last vol. p. 145), has been 
analysed by its describer with the following results : Sulphur 29*08, anti- 
mony 53*12, mercury 14*00, iron 3*50 = 99*70 ; whence the automic ratio for 
the sulphur, antimony, mercury and iron 18*17 : 8*7 : 1*4 : 1*2 = (nearly) 
15 : 7 : 1 : 1. The livingstonite occurs at Huitzuco, in the State of Guer- 
rero, in a matrix of carbonate and sulphate of lime, along with native 
sulphur, cinnabar, valentinite and stibnite. The author mentions the occur- 
rence of some specimens of cinnabar at the locality which have the form of 
livingstonite, and which, therefore, are pseudomorphous. 
What is Koppite ? — We learn from a recent number of the 11 Academy” 
that, under the name of Koppite , Professor Knop of Carlsruhe, has published 
the preliminary description of a new mineral from the Kaiserstuhl, which 
Boracic acid . 
Oxide of iron . 
Protoxide of iron 
Magnesia 
. 1609 
. 39-92 
. 12*46 
. 31*69 
100*16 
