Next page Previous page

Lake George diamond

See:Herkimer diamond

lake ore

a. See:bog iron; bog iron ore.
b. A disklike or irregular concretionary mass of ferric oxyhydroxide less
than 1 m thick; or a layer of porous, yellow bedded limonite formed along
the borders of certain lakes. See also:bog ore

Lake Superior agate

a. Any agate from the Lake Superior region.
b. Thompsonite marked or banded like agate from the Lake Superior region.

Lake Superior greenstone

See:pumpellyite

lambda plate

See:mica plate

Lambert's Law

See:translucency

lamella

A thin scale, leaf, lamina, or layer; e.g., one of the units of a
polysynthetically twinned mineral, such as plagioclase. Plural, lamellae.
AGI

lamellar

Composed of or arranged in lamellae; disposed in layers like the leaves of
a book. Syn:lamellate

lamellar flow

Flow of a liquid in which layers glide over one another.
CF:laminar flow

lamella roof

A vault or large span built up with short structural members of timber or
pressed steel, joined together in a diamond pattern by bolting or other
suitable connections. This system, which is a type of stressed-skin
construction, was patented in 1925 by a German engineer. Hammond

lamellar pyrite

See:marcasite

lamellar stellate

In mineralogy, having or consisting of lamellae arranged in groups
resembling stars. Standard, 2

lamellar twinning

Multiple parallel twins; e.g., albite twinning in plagioclase.
Syn:polysynthetic twinning

lamellate

See:lamellar

lame-skirting

Widening a passage by cutting coal from the side of it. Also called
skipping; slicing. Fay

lamina

The thinnest recognizable layer in a sedimentary rock. Plural, laminae.
CF:stratum

laminar flow

Water flow in which the stream lines remain distinct and the flow
direction at every point remains unchanged with time. It is characteristic
of the movement of ground water. CF:turbulent flow; lamellar flow.
Syn:streamline flow; sheet flow. AGI

laminar velocity

That velocity below which, in a particular conduit, laminar flow will
always exist, and above which the flow may be either laminar or turbulent,
depending on circumstances. Also known as lower critical velocity.
Seelye, 1

laminated

In very thin parallel layers.

laminated iron

Iron in the form of thin sheets; used as cores of transformers, etc. The
losses due to eddy currents with laminated iron cores are lower when
compared with solid cores. Nelson

laminated quartz

Vein quartz containing slabs, blades, or laminar films of other material.
AGI