Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/360

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350
Mr. William Phillips on the Oxyd of Tin.


Incidence of 5 on 4 fig. 49 153°. 25′
────────── 5 on 5 over the plane 4 fig. 49 126°. 45′
────────── 5 on 5 over the plane 1 fig. 49 143°. 10′
────────── 6 on 1 fig. 60. Pl. 18 168°. 40′
────────── 6 on 5 fig. 60 172°. 50′
────────── 7 on 1 fig. 66 155°. 25′
────────── 7 on 2 fig. 70 154°. 15′
────────── 7 on 7' fig. 66 159°. 5′
────────── 7'on 7' fig. 66 118°. 10′
────────── 9 on 1 fig. 114 Pl. 20 157°. ?
────────── 10 on 2 fig. 114 131°. 10 ?
────────── 10 on 2 fig. 164 Pl. 22 150°. 30 ′ ?
────────── 10 on 9 fig. 167 158°. 15′
Specific Characters.
Primitive crystal—an octahedron composed of two obtuse quadrangular pyramids joined at their bases, which are square.
Fracture—mostly shattery, often vitreous; sometimes conchoidal, sometimes lamellar.
Aspect—non metallic.
Specific gravity[1]─6,9009—6,9348 according to Haüy.
    of the crystallized grey tin-stone 6,84, Klaproth.
of stream tin 6,56, ditto.
of another ditto 6,97, ditto.
of wood tin 6,45, ditto.
Hardness—brittle and easily frangible; gives sparks with a steel.
  1. “ It is remarkable enough that tin, which, in the metallic state, is one of the lightest metals, surpasses in specific gravity, when in the state of oxyd, the greater part of other substances of the same class, whether simple oxyds or composed of an oxyd with a mineralizing substance. The weight of oxydated tin is such, that its difference with that of metallic tin is but about one twentieth at least; whilst other metals offer, in analogical instances, differences which amount to one-half or one-third.” Haüy.