Alabaster
Reference articles are in English.
A pale gypsum alabaster specimen from Pomaia, Italy. Source
Description
Gypsum alabaster is a compact, fine-grained carving stone. Calcite alabaster, traditionally called Egyptian alabaster, is a different material, often banded and described as travertine. Both may transmit light through thin sections. Pale areas, veins and changes in translucency contribute to the appearance of carved vessels, sculpture and lighting.
History
Calcite alabaster was used for vessels and other objects in ancient Egypt. Gypsum alabaster became an important material for European sculpture, including religious carving in medieval England.
Commissioning
The material should be identified as gypsum or calcite before a block is selected. For a lamp, an illuminated sample at the proposed thickness helps establish the effect. The maker should also advise on handling, display conditions and surface care.