transmitted light. Occurs in association with quartz, feldspar, and mica.
Scapolite (Wernerite),
silicate of aluminum, calcium, and sodium; in square, yellowish prisms,
also massive, frequently in gray quartz. Taken at Fort George, 155th
Street and Amsterdam Avenue, iooth Street and Lexington Avenue, and at
120th Street and 4th Avenue.
Sericite, a fine scaled muscovite, light in color, from 96th Street and 3d Avenue.
Serpentine, the
hydrous silicate of magnesium, in drift and in place; from the 10th
Avenue hills and in dolomite. Serpentine in boulders occurred in
foundations in Exchange Place.
Siderite, carbonate
of iron, found as sphero-siderite, quite commonly. With stilbite in
brown, dark spheres, in pea-form clusters on gneiss. Localities at 90th
Street and 4th Avenue, 45th Street and 1st Avenue, 70th Street and 4th
Avenue, 82d Street and 4th Avenue.
Sphalerite, sulphide of zinc, amorphous and in isolated measurable crystals in dolomite, of dark honey-brown color.
Sphene or Titanite, the
silicate of titanium and lime, has been taken out by Mr. Niven in
surprisingly handsome yellow plates implanted over black hornblende. At
the Jerome Avenue quarry the brown, flat, roof-shaped crystals are
common; but the green-yellow forms, suggestive of Tilly Foster
crystals, at Fort George and at 190th Street and Amsterdam Avenue, are
pre-eminent.
Staurolite, silicate of aluminum, iron and magnesium, reported.
Stilbite, silicate
of aluminum, calcium and sodium, with water; of superb character, light
stucco brown or yellow to chocolate tints and not infrequently white,
immensely developed at the dike, 128th to 130th Street, east of Convent
Avenue. Good specimens from Subway tunnel at Battery, 60 feet below
surface of rock. (Boniface and Atkins.)
Talc (Soapstone), hydrous silicate of magnesium, here and there as scales.
Tellurium (Graphic), reported.
Thomsonite (a zeolite), hydrous silicate of aluminum, calcium, and sodium; reported.
Topazolite, a light yellow garnet; reported.
Torbernite, phosphate of uranium and copper, in green square tables, uncommon.
Tourmaline, silicate of aluminum, iron, magnesium, with boron, much varied in composition in its different forms, is one
