Antieke juwelen glossarium
(verklarende woordenlijst)

A - B - C - D - E - F - G - H - I - J - K - L - M - O - P - Q - R - S - T - U - V - W - X - Y - Z         (alles)

Inclusion

A foreign material (solid, gaseous or liquid) usually minute in size, that is enclosed within a natural mineral, but not a synthetic gemstone. An inclusion may result from: a pre-existing material that was enveloped by a growing crystal, e.g. specks of iron; a substance formed when the crystal was being formed, e.g. a gas bubble or a change after the crystal was formed, e.g. by heating which causes chamical alteration and recrystallization.

Examples of solid inclusions may be:

• a needle of ruttle in asteria
• specks (piqués) of carbon in some diamonds
• specks of mica in aventurine quartz
• insects etc., embedded in amber

Examples of liquid or gaseous inclusions may be water or carbonic gas, with sometimes a bubble of gas in the liquid (a 'two-phase inclusion'), and sometimes also an included crystal (a 'three-phase inclusion').

From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson