a haunting feeling that to take it could be regarded as theft, as it is
probably destined for foreign ports, but a paper bagful goes a long
way and hasn't noticeably bothered our balance of trade. It is a glaze
additive only, its analysis being:
98% pyrite (FeS2)
.8% gold
0.14% chalcopyrite (CuFeS2)
0.05% sphalerite (ZnS)

As is obvious from its high iron content, it produces a brown speckle
effect which is very pleasant in amounts up to 20% by weight in all
glazes - except a few copper-loving glazes such as R17C, where it
produces that horrible matt-metallic colour typical of a copper
overload.

I have also used B, B.C. at times in a clay body, instead of grog or
silica sand, to give body and colour to the clay. Used this way, un-
glazed areas are nicely speckled and the iron bleeds through light-
coloured glazed areas, but there is a great disadvantage: during

firing choking waves of sulphur gases are released and billow out of
every crevice in the kiln, necessitating evacuation of the kiln-room.

C.M. T.

A more versatile material than B. B.C., this material is spread over
acres of land just outside Princeton. The location is familiar to
anyone who has driven by, as the now defunct company has posted a
large statistical sign on the highway. One simply drives in on the
access road, parks on the tailings, and shovels the sandy material
into the car.

C.M.T. proved to be a good addition to any glaze in any quantity,
either sprinkled into them or mixed into a heavy paste. Wedged into
clay as grog, it improves the body without the gaseous disadvantages
of B.B.C. Applied as a Cone 8, and higher, glaze, it is a variegated
brown with little tendency to run. At Cone 8 it has a pleasant, slight ly
grainy texture, but at the higher temperatures it smooths out and
darkens to a satin matt. Its main drawback is in application. I mix

it with very little water and vast quantities of gum or C.M.C. and
12.