Zanzibar copal

Description

A hard variety of Copal resin found as semi-fossilized specimens on the ground or as exudations on living trees (species Trachylobium such as T. verruscosum and T. mossambinecense), found on the island of Zanzibar and areas of nearby African mainland. The most valued pieces are fossilized specimens from trees that are no longer living. Zanzibar copal is a very hard, smooth and shiny resin that is used to make a dark oil varnish. Some specimens of Zanzibar copal are misrepresented as amber.

Synonyms and Related Terms

"Trachylobium verruscosum; copal de Zanzibar (Esp., Fr.); coplae di zanzibar (It); copale indiana (It); Zanzibar gum; East African copal; gum anime

FTIR (MFA)

Risks

• Combustible, burning with a white/yellow flame and dense smoke.

Physical and Chemical Properties

• Insoluble in most solvents, but a drop of ether may make the surface sticky.
• Once melted, the resin can be combined with oil or turpentine.
• Hardest of all copals.
• Fluoresces white under short-wave ultraviolet light.

Melting Point	240-360 C
Density	1.062-1.068 g/ml

Resources and Citations

• "Copal of Zanzibar" www.carrieagemuseumlibrary.org/copal_zanzibar.htm from original publication in New York Coach-Maker's Magazine, August 1870.

• R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 227

• Encyclopedia Britannica, http://www.britannica.com Comment: "Copal." Accessed 5 Jan. 2004 - gives source of Zanzibar copal as Trachylobium verruscosum

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000

• Website: "Copal: An Immature and Controversial Resin" at www.emporia.edu/earthsci/ambe/copal.htm - gives source of Zanzibar copal as Trachylobium verruscasum (formerly called Hymenaea verrucosa)

• "Varnish Glossary" at www.violins.on.ca/luthier/vargloss.html - gives synonyms as gum anime and East African copal