An opal, e.g., hydrophane, artificially impregnated with melted wax.
See also:fire opal
A trigonal mineral, MnTiO3 ; ilmenite group; forms a series with
ilmenite; blood red.
A variety of sphalerite that gives off sparks or glows when abraded. Some
pieces are so sensitive that the effect is obtained by scratching them
with a fingernail. Hess
A monoclinic and triclinic mineral, Al2 Si4 O10 (OH)
2 ; foliated; soft; in schists and hydrothermal veins in North
Carolina, California, Newfoundland, and Japan. Syn:pencil stone
See also:G stone
A coarse opaque variety of topaz from Finbo, Sweden. Also spelled
physalite.
An earthy nonphosphatic pyrobitumen composed primarily of water, humic
acid, wax (a source of "montan wax"), and silica, associated with brown
coal called pyropissitic brown coal.
A self-contained instrument with the millivoltmeter mounted in the
pyrometer tube; the radiant energy is concentrated by means of an
objective lens (quartz or fluorite) rather than by a reflecting mirror.
Newton, 2
A brittle, brownish-black resin that occurs in brown coal near Aussig,
Bohemia; sp gr, 1.05 to 1.18. Fay
Any member of the hexagonal mineral series,
ferropyrosmaltite-manganpyrosmaltite, (Fe,Mn)8 Si6 O (sub
15) (OH,Cl)10 .
See:kermesite
See:kermesite
A monoclinic mineral, Ag3 SbS3 ; dimorphous with
pyrargyrite; red. Syn:fireblende
a. A heavy, oily, strongly corrosive liquid H2 S2 O7
that consists of a solution of sulfur trioxide in anhydrous sulfuric acid.
It fumes in moist air and reacts violently with water with the evolution
of heat. Webster 3rd
b. A solution of sulfur trioxide in sulfuric acid; H2 S2 O
7 . Colorless to dark brown depending on purity; hygroscopic.
CCD, 2
a. A group of chiefly magnesium-iron minerals including diopside,
hedenbergite, augite, pigeonite, and many other rock-forming minerals.
Although members of the group fall into different systems (orthorhombic,
monoclinic, and triclinic), they are closely related in form, composition,
and structure. See also:acmite; aegirite; augite; diallage; enstatite;
hypersthene. Fay; AGI
b. The mineral group aegirine (Ae), aegirine-augite, clinoenstatite,
clinoferrosilite, diopside (Di), donpeacorite, enstatite (En), essenite
(Es), ferrosilite (Fs), hedenbergite (Hd), jadeite (Jd), jervisite (Je),
johannsenite (Jo), kanoite (Ka), kosmochlor (Ko), natalyite, omphacite,
petedunnite (Pe), pigeonite, and spodumene (Sp). Some former names
relegated to synonyms include acmite = aegirine, bronzite = enstatite,
clinohypersthene = clinoenstatite or clinoferrosilite, diallage = altered
diopside or other pyroxene with good (100) parting, eulite = ferrosilite,
fassaite = ferrian aluminian diopside or augite, ferroaugite = augite,
ferrosalite = hedenbergite, hiddenite = spodumene, hypersthene = enstatite
or ferrosilite, kunzite = spodumene, salite = diopside, titanaugite =
titanian augite, uralite = pseudomorphous amphibole after pyroxene, and
ureyite = kosmochlor. Pyroxenes (px) are either monoclinic
(clinopyroxenes, cpx) or orthorhombic (orthopyroxenes, opx). General
formula: AB2 ZO6 : A = Ca, Fe2+ , Li, Mg, Mn (super
2+) , Na, Zn; B = Al, Cr3+ , Fe2+ , Fe3+ , Mg,
Mn2+ , Sc, Ti, V3+ ; Z = Al, Si. Their structures are
built from single chains of silica tetrahedra each sharing two oxygens,
with a silica:oxygen ratio of 1:3, electrostatic neutrality being
maintained by cross-linking cations. Crystals are prismatic with prismatic
cleavage at 87 degrees and 93 degrees . Colors are mostly greens, but
range from white to black. Etymol: Greek pyros (fire) + xenos (stranger)
from a mistaken belief that they were only accidently caught up in lavas.
See also:aegirine
Lamellar intergrowths of pyroxene of different kinds, as with the
feldspars. Also pyroxene microperthite, pyroxene cryptoperthite.
English
A coarse-grained, holocrystalline igneous rock consisting of 90%
pyroxenes. It may contain biotite, hornblende, or olivine as accessories.
CTD
Single-chain silicates with individual silica tetrahedra twisted relative
to the pyroxene chains, resulting in triclinic symmetry; e.g., the
wollastonites, rhodonite, and pectolite.
A triclinic mineral, MnSiO3 ; forms a series with pyroxferroite
where iron replaces manganese; forms brown cleavable masses near Iva, SC;
Homedale, ID; Sweden; and Scotland.
See:pyrochlore
See:berzeliite
See:pyrrhotite