TITANIUM. 
433 
SPHENE. 
[From the Greek <fcpr\v, a wedge; probably in reference to the form of some of its crystals.] 
Titane Siliceo-Calcaire. Huuy .— Silico-Calcareous Oxide of Titanium. Ckaveland .— Sphene. Phillips, Thomson, 
Shepard and Beudant. — Hemiprismatic Titanium-Ore. Jameson. — Prismatisches Titan-Erz. Mohs. 
Fig. 51S. 
Fig. 520. 
Description. Colour yellow, brown, green and 
grey, usually dull. Streak greyish white. It occurs 
regularly crystallized ; also massive, in granular and 
lamellar distinct concretions. Primary form an 
oblique rhombic prism. Fig. 519. M on M / 133° 
30'; P on M 121° 50 / (Phillips and Beudant). 
Fig. 520. M on W 76° 2'; M or M' on P 93° V 
{G. Rose and Thomson). Cleavage parallel to the 
faces of the primary prism, but not distinct. Fracture 
imperfect conchoidal. Lustre adamantine, some¬ 
times inclining to resinous. Varies from transparent to opaque. Hardness from 5.0 to 5.5, 
Specific gravity from 3.49 to 3.60. Before the blowpipe, it fuses with difficulty into a dark 
coloured enamel; with borax, it affords a yellowish green diaphanous glass. It is soluble in 
heated muriatic or nitric acid, leaving a siliceous residue. By boiling, the titanic acid is pre¬ 
cipitated. 
Composition. Oxide of titanium 33.00, silica 35.00, lime 33.00, trace of manganese 
{Klaproth). Titanic acid 48.00, silica 33.00, lime 19.00 {Rose). The latter results, it 
will be observed, differ considerably from those obtained by Klaproth and Cordier. 
Geological Situation. This mineral occurs in small nodules or crystals in granite, gneiss, 
and primitive limestone. In this State, it is most frequently found in the latter rock. 
Essex County. Sphene was first noticed as a New-York mineral, in the vicinity of Ticon- 
deroga, by the late Col. Gibbs.* The crystals were described as having a yellowish grey 
colour, and the form of rhoraboidal prisms terminated by dihedral summits. They were 
imbedded in an aggregate of white granular and lamellar feldspar. 
Dr. Bruce has also described, as from the vicinity of Lake George, probably from Rogers’ 
rock, large clove-brown crystals in form similar to that of Fig. 521, imbedded in a rock com¬ 
posed of hornblende, feldspar and foliated graphite. 
At Rogers’ rock, crystallized sphene is very abundant, and is associated with pyroxene and 
graphite. The crystals are of various sizes, have a brown colour, and exhibit the forms 
represented in Figs. 522, 523 and 524. M or M / on a 139° 30'; P on e 2 158° 18'; c on d, 
146° 44'; c on e 145° 18'; e 2 on e 2 136° 50' {Phillips). 
9 American Mincralogical Journal , 239, 
55 
Min. — Part II. 
