Buddhue, 1935; Tschirch and Stock, 1936), but it has 
neither been analyzed chemically and physically nor been 
given a mineralogical name. The geologic occurrence 
was first recorded by Bose in 1905. A coordinated scien- 
tific investigation was initiated by entomologists and 
later included geologists and botanists (Hurd and Smith, 
1957; Hurd, Smith and Durham, 1962; Langenheim, 
1964, 1966, 1967; Langenheim, Hackner, and Bartlett, 
1967). 
The amber-bearing beds are ina sequence of primarily 
marine, caleareous sandstones and siltstones which are 
mostly exposed in landslides. All amber-bearing locali- 
ties are considered latest Oligocene to earliest Miocene 
in age, based on marine invertebrate fossils (Licari, 1960; 
Hurd, Smith and Durham, 1962). Pollen from the strata 
either containing the amber or immediately adjacent to 
them indicates development of mangrove vegetation of 
considerable complexity at or close to the site of depo- 
sition of the amber (Langenheim, Hackner and Bartlett, 
1967). 
Previous discussions have presented evidence support- 
ing the conclusion that this amber was derived from the 
leguminous genus Hymenaea (Langenheim, 1963; Lan- 
genheim and Beck, 1965; Langenheim, 1966; and 
Langenheim, 1967). Spectra were made of various resins 
from populations existing in Chiapas today. Each genus, 
as well as certain species populations, was clearly dis- 
tinghishable. Remarkably consistent spectra were ob- 
tained from 35 samples of Hymenaea Courbaril L. from 
various populations in Mexico, Guatemala, Dominica, 
Costa Rica, Guyana, Venezuela, Brazil and Ecuador. 
Forty specimens of Chiapas amber from the University 
of California, Museum of Paleontology Collections from 
various localities were chosen for spectra because they 
showed some difference in physical character. The color 
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