tassium,
in very pretty crystallizations of interpenetrating cruciform twins,
discovered by Mr Chamberlin on surfaces of gneiss and associated with
chabazite and stilbite; of two colors, dark brown and yellow. It is a
hydrated silicate of aluminum, barium, and potassium. It is also found
as flesh-red crystals of considerable size in strings, through seams in
gneiss at o,2d Street.
Heulandite, a
hydrated silicate of aluminum and calcium, found in faintly colored
straw-yellow crystals, lamellar, pearly, deepening in tint to reddish
yellow.
Hydrodolomite, a somewhat nondescript mineral, probably a hydrous carbonate of calcium and magnesium, reported.
Hypersthene, a
ferro-magnesian silicate in the pyroxene group; reported from builders.
Improbable; the material seen is broad-bladed hornblende, which does
occur in the Palisade dolerite.
Idocrase (Vesuvianite), reported, improbable. It is a basic calcium aluminum silicate.
Iolite, a
silicate of aluminum, iron, and magnesium, found by Niven, identified
by Hidden, from 170th Street and Amsterdam Avenue (Fort George);
gray-green, green-blue in color; polished fragment in the Kunz
collection. Rare.
Jasper, form of quartz, massive, opaque, in pebbles in drift; reported along Harlem River.
Jefferisite, a
micaceous mineral very much hydrated, a silicate of aluminum, iron, and
magnesium, when highly heated swelling, exfoliating, and becoming
white and opaque. Uncommon; found at 100th Street and Fifth and Third
Avenues, marked as coming from cavities in gneiss, also in polyhedral
surfaces, perhaps coating interior minerals.
Kaolin, Kaolinite, clay,
decomposition of feldspar; a good example from 56 feet below curb at 12
and 14 West 32d Street (A. S. Coffin, C. E.) is in the Mineralogical
Club collection.
Kyanite (or
Cyanite), silicate of aluminum, is a blue to green, flat-bladed
mineral, which has been found abundantly at one or two points and is
sparingly distributed elsewhere. The place of its extreme abundance was
at 101st Street and 3d and Lexington Avenues. It also forms a local
schist and has been so regarded. " Between the blades of kyanite
appeared a deep-hued smoky quartz, also garnets and scapolite." Camp
observed it on Convent Avenue at 128th to 130th Streets.
Laumontite, a hydrated silicate of aluminum and calcium; reported, rare.
