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desert rose

A radially symmetrical group of crystals with a fancied resemblance to a
rose, formed in sand, soft sandstone, or clay. These crystals are commonly
calcite, less commonly barite, gypsum, or celestine.

desert varnish

A thin dark shiny film or coating, composed of iron oxide accompanied by
traces of manganese oxide and silica, formed on the surfaces of pebbles,
boulders, and other rock fragments in desert regions after long exposure,
as well as on ledges and other rock outcrops. It is believed to be caused
by exudation of mineralized solutions from within and deposition by
evaporation on the surface. See also:patina

desiccant

A substance having an affinity for water. Used for drying purposes.
Bennett

desiccate

To dry; to remove moisture; to preserve by drying. Webster 3rd

desiccation

A drying out, as in loss of water from sediments, or evaporation from
water bodies in arid regions, producing evaporites.

desiccation crack

See:mud crack

desiccator

A short glass jar fitted with an airtight cover and containing some
desiccating substance (as calcium chloride), above which is placed the
material to be dried or to be protected from moisture. Webster 3rd

design

A type of diamond-drill fitting that, when standardized, has specific
dimensions and thread characteristics establishing interchangeability of
parts made by different manufacturers, and size by specific dimension of
the set core-bit inside diameter. Design characteristics supplement the
group characteristics that provide for integration of ranges. The design
characteristics of drill fittings are established by the second letter in
two-letter names and by the third letter in three-letter names. Letters
denoting design may establish interchangeability of all parts, as in the
M-design core barrel, or only of certain parts, as in the X-design core
barrel. CF:group; range. Long

designated size

The particle size at which it is desired to separate a feed by a sizing
operation. BS, 5

designed borehole deflection

The turning of a borehole along a different course at depth. This may be
achieved, but not without difficulty. The cutting bit is guided upon its
new course by the curved surface of a deflecting wedge that is positioned
with the aid of a modified Oehman instrument. In petroleum drilling, much
use is made of holes that are deflected at a predetermined depth. The
technique is known as whipstocking. Nelson

design horsepower

The specified horsepower multiplied by a service factor. It is the value
used to select the chain size for a chain drive. Jackson, 1

desilication

The removal of silica from a rock or magma by the breakdown of silicates
and the resultant freeing of silica, or by reaction between a body of
magma and the surrounding wall rock. AGI

desiliconizing

A practice of jetting oxygen into pig iron before it is charged into the
steel furnace; this oxidizes and removes most of the silicon.
Newton, 1

desilverization

The process of removing silver (and gold) from lead after softening.
See also:Parkes process; Pattinson process. CTD

desliming

The removal of slimes from coal or a mixture of coal and water, however
accomplished. BS, 5

desliming screen

A screen used for the removal of slimes from larger particles, usually
with the aid of water sprays. BS, 5

deslurrying

Fines removal by wet methods. BS, 5

desmine

A former name for stilbite.

desmite

The amorphous groundmass, which is transparent in thin sections, binding
together the constituents of bituminous coal of high grade. Applies to the
transparent variety of residuum found in high-grade coals.
Tomkeieff

desmosite

A banded adinole. AGI

desorption

The reverse process of adsorption whereby adsorbed matter is removed from
the adsorbent. The term is also used as the reverse process of absorption.