Natural Science in Archaeology

324 Glossary
Radiolarian Pertaining to material composed of siliceous skeletal material from
marine radiolaria fossils.
Reducing atmosphere An atmosphere where oxygen is absent and elements can be
reduced by gaining electrons, usually by the concomitant conversion of CO·CO 2 .
Refractory Said of a material that is exceptionally resistant to heat; having a high
temperature of softening or melting.
Schistose A metamorphic rock texture displaying foliation due to the parallel alignment
of platy minerals such as mica.
Shear (resistance to) Resistance of a material to deformation resulting from
stresses that cause parts of the material to move relative to each other.
Shield A large area of very old, exposed, tectonically stable, rocks surrounded by
younger sedimentary rocks.
Sintering A solid-state process by which bonds develop at high temperatures
between grains of solid material brought into contact.
Slag A furnace product resulting from the fusion of waste material (principally iron
and silica) after the separation of the metal phase.
Slake To treat lime with water to give hydrated lime.
Sluice A conduit for carrying off surplus water, often at high velocity. It can be
used to concentrate heavy minerals such as gold or cassiterite.
Smalt A smelted product using a pigment and colorant; composed of cobalt, aluminum,
and potassium silicates.
Smelting A pyrotechnology for separating a metal from the rest of an ore, normally
by inducing a liquid metal phase and a liquid slag phase.
Sol Denotes a homogeneous suspension of colloidal matter in a fluid or a completely
mobile mud (more fluid than a gel).
Supratidal The shore area just above the high-tide level.
Tawing To convert skin into white leather by mineral tanning as with alum and salt.
Tell A mound site formed by successive human occupations over a considerable
period of time.
Telluric iron Metallic iron that has formed naturally in the earth rather than produced
from smelting.
Tempera A general term applied to a type of paint in which the pigment is suspended
in an albuminous, gelatinous, or colloidal medium. Egg, gum, and glue were
all used to manufacture tempera in antiquity.
Tensile strength The maximum stress that tends to pull a material apart that can be
applied to a material before rupture starts.