| Macle |
A natural diamond crystal in the
form of a flat shollow triangle. |
| Make |
The cut of a diamond. The
quality of th emake affects the value of the stone. |
| Malleability |
The ability of a metal to be
hammered or rolled into thin sheets. Gold is the most malleable of all metals. |
| Marcasite |
The name commonly given to cut
iron pyrite crystals used in jewellery. True marcasite is seldom used for jewellery. |
| Marquise
cut |
A variation on the brilliant
cut. A marquise diamond is boat shaped. |
| Massive |
A micro-crystalline mineral in
which the crystal form is not apparent to the eye. Agate is a massive quartz. |
| Matrix |
The native rock in which metal
and gem crystals were formed. |
| Milanese |
Small links of metal woven
together to form a ribbon. |
| Melee |
An assortment of small diamonds
under a quarter of a carat in weight. |
| Mixed cut |
A cut commonly used for coloured
stones. The table facets are the same as for a brilliant cut but the pavilion facets
are the same as those of a step-cut stone. |
| Mohs' scale |
An arbitrary scale of hardness
from 1 fro talc to 10 for diamond introduced by F. Mohs. |
| Mount |
The metal part of a piece of
jewellery in which the stones are set. |
| Mother of
pearl |
A sleek calcium carbonate layer
taken from the inside of an oyster or other mollusc shell. |