Mexican amber is fossil resin recovered chiefly from the Simojovel region of Chiapas in southern Mexico. The deposits sit in shales and lignites of late Oligocene to early Miocene age, roughly twenty-three to thirty million years old, formed from the resin of an extinct leguminous tree closely related to Hymenaea. The same genus is responsible for Dominican amber, and the two materials share a great deal of botanical and palaeontological character.

The colour range runs from pale lemon and warm honey through cherry red, brandy and the prized blue and green fluorescent stones. Blue Chiapas amber, like its Dominican counterpart, owes its appearance to fluorescence under ultraviolet wavelengths present in daylight, not to body colour. Specific gravity sits near 1.05 and refractive index near 1.54, with hardness of two to three on the Mohs scale. The resin is generally clean, takes a soft polish and feels warm to the touch, all consistent with succinite-class amber.

The mining is artisanal. Small underground workings at Simojovel, Huitiupan and Totolapa are operated by Tzotzil and Tzeltal communities, with the gem cut locally and sold through cooperatives and the markets of San Cristobal de las Casas. Production is modest by global standards, and the rough often arrives at the bench in irregular nodules or sheets that limit cutting size.

The fossil inventory is the scientific draw. Insects, spiders, plant fragments, microbial mats and even the occasional vertebrate fragment have been described from Chiapas amber, with peer-reviewed work in the palaeontological literature establishing the deposit as one of the more important Cenozoic Lagerstatten in the Americas. For the trade, inclusions add interest but are sold separately from clean ornamental rough.

Treatment and imitation are real concerns. Heat clarification in oil is documented, as is pressing of small fragments into larger ambroid blocks. Copal, a much younger and softer resin from the same region, is sometimes mis-sold as amber and can be distinguished by its lower melting point, solubility in alcohol and immature aromatic profile. A buyer should expect a reputable dealer to identify the material specifically as Chiapas amber and to disclose any treatment.

In the Mexican market the stone carries cultural weight that extends beyond gemmology. It has been carved, beaded and inlaid in regional silverwork for generations, and Chiapas has formal denomination of origin protection for amber under Mexican federal law, recognised since 2000.