a. A mixture of chalcocite and silver.
b. A silver-gray copper silver sulfide found at Ramos, Mexico; perhaps a
variety of stromeyerite.
a. An open-space vein filling in which the ore and gangue minerals are
deposited in successive comblike crusts around rock fragments; e.g.,
around vein breccia fragments. Syn:cocarde ore; sphere ore.
See also:ring ore
b. Cockscomb pyrite; a form of marcasite.
The form taken by cockade ore.
To set supports in herringbone fashion. Mason
Herringbone supports. A method of support by which a center support of
beams or bars running longitudinally along the roof of a road is supported
systematically by slanted struts or props with their feet spragged in the
side of the road, the whole looking like a herringbone. Mason
Temporary support for the coal face. A short crosspiece is held to it by
two slanting props, one hitched in the floor, the other in the roof.
Pryor, 3
See:cockermeg
See:cockermeg
a. Corn. Schorl or black tourmaline. Fay
b. Any mineral occurring in dark, long crystals, esp. schorl.
Webster 2nd
c. Eng. A black, thready mineral, seeming to be a fibrous talc; occurs in
Cornish tin mines. Arkell
d. Eng. An ironstone nodule. Arkell
e. Cornish name for hard siliceous rocks. Arkell
A piece of slate or bony. Korson
See:marcasite
A crestlike variety of marcasite. See also:marcasite
Webster 3rd
A fabric of wood fibers used to distribute water evenly over a smooth
surface. Nichols, 1
A highly siliceous hematite containing only a trace of phosphorus, but
high in potash. Osborne
coefficient of absolute viscosity
A ratio, calculated from the normative molecular proportions of the
constituents of a rock or slag; e.g., number of atoms of oxygen in SiO
2 / number of atoms of oxygen in the basic oxides.
coefficient of compressibility
The decrease in volume per unit volume produced by a unit change of
pressure. Webster 2nd
a. A numerical expression of the relationship between pressure and the
resistance force of friction.
b. A quantity used to calculate the head loss in a fluid or air. The loss
is a function of surface roughness, wetted perimeter, and velocity of the
fluid or gas.
coefficient of heat transmission
The quantity of heat transmitted from fluid to fluid per unit of time per
unit of surface area through a material or arrangement of materials under
a unit temperature differential between fluids. Commonly used for building
materials. Syn:heat transmission coefficient
The rate of flow of water under laminar flow conditions through a unit
cross-sectional area of a porous medium under a unit hydraulic gradient
and a standard temperature, usually 20 degrees C.
See also:permeability