A monoclinic mineral, Fe2 (SO4 )3 .7H2 O ;
forms rose to violet prisms; an alteration of pyrite.
An orthorhombic mineral, Mg4 (Al,Fe)6 (Si,B)4 O (sub
21) (OH) ; forms columnar crystals with prismatic cleavage; in high-grade
metamorphic aluminous rocks.
A mineral, CaB2 O4 .H2 O ; in skarns with other
calcium borate minerals.
A monoclinic mineral, Zn3 (AsO4 )2 .8H2 O ;
vivianite group; forms a series with parasymplesite; carmine-red with one
perfect cleavage; occurs with smaltite at Schneeberg, Saxony, Germany.
Also spelled koettigite.
A hexagonal mineral, Pd(Te,Bi) .
A dust-sampling instrument consisting of an air cylinder and piston
actuated by a spring, and so arranged that on release of the piston a
known volume of air is impinged at high velocity against a plate coated
with vaseline. The dust spot so produced is examined under the microscope,
and a count is made of the number of particles. Greenburg
An etchant for steel; it consists of seven parts of a solution containing
20% methyl alcohol, 20% ethyl alcohol, 20% iso-amyl alcohol, and 10% butyl
alcohol added to three parts of a solution of 4% nitric acid in acetic
anhydride. This etchant colors sorbite and troostite, leaving the other
constituents unaffected. Osborne
A hexagonal mineral, Cu5 As2 .
See:probertite
A fossil resin resembling amber and found in small yellowish grains
disseminated in brown coal. Tomkeieff
An orthorhombic mineral, C13 H10 .
See:dufrenite
A monoclinic mineral, KFe(SO4 )2 .H2 O ; forms soft
yellowish-green prismatic crystals and crusts.
An orthorhombic mineral, (NH4 ,K)2 FeCl5 .H2 O;
forms red pseudo-octahedra around fumaroles in Sicily, Italy.
One of the gold telluride group of minerals, (Au,Ag)Te2 ;
corresponds to the same general formula as sylvanite and calaverite.
Silver-white to pale yellow color; sp gr, 8.35. Found in Colorado and
Romania. Syn:white tellurium
a. A weighted, moving-average interpolation method in which the set of
weights assigned to samples minimizes the estimation variance, which is
computed as a function of the variogram model and locations of the samples
relative to each other, and to the point or block being estimated.
b. In the estimation of ore reserves by geostatistical methods, the use of
a weighted, moving-average approach both to account for the estimated
values of spatially distributed variables, and also to assess the probable
error associated with the estimates. SME, 1
The standard error of estimation computed for a kriged estimate. By
definition, kriging is the weighted linear estimate with the particular
set of weights that minimizes the computed estimation variance (standard
error squared). The relationship of the kriging standard deviation to the
actual error of estimation is very dependent on the variogram model used
and the validity of the underlying assumptions; therefore, kriging
standard deviations should be interpreted with caution.
The treatment of silver ores preparatory to amalgamation, by humid
chloridization with copper dichloride. Fay
A monoclinic mineral, Na2 Cu(SO4 )2 .2H2 O ;
azure; in Chilean copper deposits. Also spelled kroehnkite.
Process in which purified titanium tetrachloride is reduced to the
metallic state with magnesium in an inert atmosphere of helium or argon.
a. See:Krupp washing process
Fay
b. A cementation process designed for the hardening of surface steel, as
for armor plates, where the object is to strengthen the outer portion of
the mass from the surface toward the interior. Standard, 2