Said of the texture of a porphyritic igneous rock in which the groundmass
is composed of an aggregate of differently oriented or parallel microlites
in a glassy or cryptocrystalline mesostasis. AGI
Essentially a U-type gage employing a micrometer to measure the change in
inclination of the gage from its zero or datum position. Normally,
micromanometers are used in the laboratory for such purposes as the
calibration of secondary manometers and, in conjunction with pressure
measurement, in low-speed atmospheric wind tunnels. See also:manometer
Roberts, 1
An obsolete syn. of microcrystalline. See also:microcrystalline
AGI
a. An instrument for measuring very small dimensions or angles. Used in
connection with a microscope or a telescope. There are a great variety of
forms, but in nearly all, the measurement is made by turning a very fine
screw, which gives motion to a scale, a spider line, a lens, a prism, or a
ruled glass plate. Standard, 2
b. A unit of length, equal to one-millionth of a meter. Symbol, mu m. (1
mu m = 10-6 m). Formerly called micron.
c. A micrometer caliper. Standard, 2
A caliper with a graduated screw attachment for measuring minute
distances. Crispin
The study of very fine particles. AGI
One-millionth of a millimeter; abbrev., mmu . AGI
Former term for micrometer.
An ultrafine material produced in a disintegrator that has no moving parts
but depends on jets of high-pressure superheated steam to reduce the mica
to micrometer sizes. Micronized mica is produced in particle size ranges
of 10 to 20 mu m and 5 to 10 mu m. USBM, 7
A special type of dry-grinding machine in which micronized mica is
produced. It consists of a disintegrator that has no moving parts but
depends on jets of high-pressure superheated steam for reducing the mica
to micrometer sizes. USBM, 7
Disintegrator, in which feed particles are entrained in a pressure jet
(steam or air) and whirled through a cylindrical chamber with sufficient
force to break them. Pryor, 3
A less-preferred syn. of granophyre. See also:granophyre
Exsolution lamellae in alkali feldspar visible only with the aid of a
microscope. See also:cryptoperthite; perthite.
See:maceral
See:photomicrograph
Porosity visible only with the aid of a microscope. ASM, 1
An instrument used to produce enlarged images; it consists of a lens (or
lenses) of the objective and an ocular set into a tube, with or without
other accessories, and held by an adjustable arm over an object stage.
a. Of, relating to, or conducted with a microscope or microscopy.
Webster 3rd
b. So small or fine as to be invisible or not clearly distinguishable
without the use of a microscope. CF:macroscopic; megascopic.
Webster 3rd
The art and practice of using a microscope for identification and analysis
of objects. See also:ore microscopy; reflected-light microscope.
One-millionth of a second; abbrev.: mu sec, mu s. Webster 3rd