Minerals having a texture of many small grains.
A condition where two or more minerals have the same composition, but
different crystal classes owing to changed bond angles; e.g., alpha and
beta quartz. CF:polytypy; polytropy; polymorphism.
a. Two systems of lamellar twinning at an angle with one another.
b. Successive twinning of three or more individuals, according to the same
twin law, with parallel composition planes; commonly revealed by visibly
striated cleavage planes; e.g., albite twinning in plagioclase feldspar.
CF:cyclic twinning; twin laminae.
Any of several acids in a series related to sulfurous and thiosulfuric
acid. Pryor, 3
A condition in which there is no change in the geometrical symmetry of the
crystal structure of two related minerals, but a change to permit a
variant in the resultant mineral; e.g., orthoclase microcline.
CF:polytypy; polysyngony. Hess
a. A condition in micas and similar clay minerals in which they show
growth spirals which are due to lamellae of different orientations.
AGI
b. One-dimensional polymorphism resulting from alternate stacking of
identical layers; e.g., kaolinite, nacrite, and dickite. Syn:polytypy
A condition in which the space lattice of two related minerals is
completely altered to a new type. This is illustrated by the
quartz-tridymite relationship. See also:polytypism
polytropy. Hess
A resin, with a plasticizer. Provides the interlayer in standard laminated
glass made from either polished plate glass or window glass. Lee
A variety of native platinum alloyed with iron.
A kind of undershot waterwheel suitable for falls of less than 6 ft (1.8
m), having the buckets curved so that the water presses on them without
impact.
A furnace in which the escaping combustion gases, passing through tubular
flues, heat the incoming air continuously through the flue walls.
Fay
An iron rod used in glassmaking to carry and manipulate hot bottles, etc.;
has a projection at the end, varying in shape according to the character
of the ware carried. Also called snap; pontee; ponto; ponty; puntee;
puntil; punty. Standard, 2
a. A float supporting part of a structure, such as a bridge.
Nichols, 1
b. A wood platform used to support machinery on soft ground.
Nichols, 1
A small timber set or frame incorporated in the main sets of a haulage
level to accommodate an ore chute or other equipment from above or below.
Nelson
a. To undercut or undermine material, such as coal, esp. in excavating.
Webster 3rd
b. A continuous area of porous sedimentary rock that yields petroleum or
gas on drilling. Webster 3rd
A screen that is divided into alternate transverse screen cloth panels and
metal plate pool sections. Water is directed to the pools, setting up a
swirling motion that agitates fines into suspension.
See also:vibratory screen
Toxic or irritating chemicals produced by an explosion. Nichols, 1
a. A short, secondary drill hole blasted to reduce larger pieces of rock
or to trim a working face. Also called pophole; pop shot.
See also:pop shot
b. Explosion in sealed area of a mine. Manometers may record a sudden
pressure rise due to such an explosion. Sinclair, 1
To place and explode a stick of dynamite on a boulder so as to break it
for easy removal from a mine. Fay
A secondary drill hole. See also:pop