A tetragonal mineral, BaTi₆ Cr₂ O₁₆ .H₂ O ;
cryptomelane group. Formerly called chromrutile.

A red mud to which lime, caustic soda, or quebracho, has been added. The
pH is usually 12.0 to 13.0.

Any reddish manganese mineral, i.e., rhodonite and rhodochrosite. Also
called red manganese ore.

Alleged to be a compound of mercury and antimony, and described in the
press to be an ingredient of explosives or nuclear weapons manufacture or
possibly a descriptive term employed to mask illicit trading activity
involving controlled substances. SME, 1

red metal

a. A copper matte containing about 48% copper. Fay
b. Any one of several alloys used in the manufacture of silverware.
Fay

red mud

a. A reddish-brown terrigenous deep-sea mud that accumulates on the sea
floor in the neighborhood of deserts and off the mouths of great rivers;
contains calcium carbonate up to 25%. Hunt
b. A clay-water-base drilling fluid containing sufficient amounts of
caustic soda and tannates to give a pronounced red appearance. The pH is
usually 10.0 to 13.0. Brantly, 1

red ore

Hematite ore.

red orpiment

See:realgar

red oxide of copper

See:cuprite

red oxide of zinc

See:zincite

redox potential

Oxidation-reduction potential. AGI

redrill

To reopen a borehole by redrilling after it has been cemented, caved, or
lost because of junk in the hole. Also called drill out, drilled out.
CF:overlap

red roast

In fluidization roasting, conversion of iron from sulfides to red oxide.
Pryor, 3

redruthite

Corn. Copper glance. See:chalcocite

reds

High explosive; used in mines. Bennett

red schorl

See:elbaite; rubellite; rutile.

redsear

In ironworking, to break or crack when red-hot, as iron under the hammer.
Standard, 2

red silver

A red silver sulfide; esp. pyrargyrite and proustite.
Syn:red silver ore

red silver ore

See:red silver