Zanzibar copal

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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- Zanzibar Copal.jpg


Other Properties

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

Melting Point 240-360
Density 1.062-1.068

Hazards and Safety

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

Additional Information

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

Sources Checked for Data in Record

  • 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." Encyclopædia Britannica. 2004. 5 Jan. 2004 . - gives source of Zanzibar copal as Trachylobium verruscosum
  • Website address 1 Comment: "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)
  • Website address 2 Comment: "Varnish Glossary" at www.violins.on.ca/luthier/vargloss.html - gives synonyms as gum anime and East African copal

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