In any market in San Cristóbal de las Casas there is amber. Pendants, spheres, figurines, pieces with an insect inside. It is sold as a souvenir and looked at as costume jewellery, and it is in fact one of the most peculiar things the state produces: a fossil material, with a designation of origin and an extraction calendar set by the rain.
01 A resin from twenty million years ago
Amber is neither a stone nor a mineral: it is fossilised tree resin. Spectroscopic analyses indicate that Chiapas amber was produced by an extinct species of the genus Hymenaea, a legume related to the guapinol that still grows in the American tropics.
Its age falls between 23 and 15 million years, in the Early and Middle Miocene. The material sits in two geological formations, Mazantic and Balumtum, which outcrop in several municipalities of the Altos.
What the inclusions reconstruct is a landscape that no longer exists here: a tropical forest dominated by those legumes, beside an estuarine environment similar to a present-day mangrove. Where today there is mountain at 1,500 metres, there was then coast.
02 The tunnel and the season
Extraction looks nothing like a quarry. Amber appears in thin seams inside mudstones and sandstones, and following them means opening narrow galleries, almost always without shoring, where the work is done lying down or kneeling with a steel hammer and chisel.
The yield is low: on the order of two to three kilos a month per miner, counting everything that comes out, not only the gem-quality pieces. And because the work is manual and artisanal, that figure has barely changed over the years.
Hence the figure that organises everything else. Those unshored tunnels become unworkable when the ground saturates with water, so extraction concentrates in the dry season, roughly January to May. In San Cristóbal, those are the months recording between 4.4 and 138 millimetres of rain; in June it jumps straight to 238.
A twenty-million-year-old material with a working calendar set by this year's rain.
03 What is inside
Fresh resin worked as a trap. Whatever landed on it was caught and, as the material polymerised, was preserved with a level of detail no other kind of fossil reaches: wings, hairs, legs and sometimes internal structures.
Around 176 arthropod families have been identified in Chiapas amber, among them insects, arachnids, myriapods and crustaceans, plus leaves, flowers and pollen. It is an inventory, not a collection of curiosities.
That inventory has value precisely because of the detail. An insect in amber allows a species to be identified and the surroundings reconstructed, which is why pieces with good inclusions are worth far more and sometimes end up in a laboratory instead of a shop window.
04 A protected name and a standard
Because amber is easy to fake, the material has its own legal protection. The designation of origin 'Ámbar de Chiapas' was granted on 15 November 2000, and in October 2001 it was registered internationally under the Lisbon system.
Three years later came the technical standard defining what may be called that: NOM-152-SCFI-2003, published on 25 August 2003. It establishes that amber is fossilised plant resin and recognises up to thirty distinct tones.
The palette runs from pale amber to translucent yellow-green, transparent reddish yellow, ruby red, near-black red, brown, milky and green. That variety, rather than the textbook yellow, is what distinguishes the Chiapas material.
05 How to tell it from the fake
What is sold as cheap amber is usually something else: recent unfossilised resin, dyed plastic, or genuine amber reconstituted from pressed fragments. The price difference is enormous and the visual one minimal to the naked eye.
The usual checks are simple. Amber is very light and warms to the touch instead of staying cold like glass. Rubbed, it becomes charged and attracts small bits of paper. And held against the light it shows irregular veining and bubbles, never a perfectly uniform colour.
The most reliable check, however, is provenance: buy where they can tell you which mine the piece came from and who worked it. With a designation of origin in force, that question has an answer.
06 What to do with all this
The first thing is to change the frame. A piece of amber is not a generic souvenir: it is a datable fragment of a forest that stood here twenty million years ago, extracted by hand from a narrow gallery during the months when it does not rain.
The second is to look before buying. The amber museum in San Cristóbal shows the material backlit, which is how colour and inclusions really appear, and it calibrates the eye before entering any stall.
And the third is to accept the price. Two or three kilos a month per miner, five months of extraction a year and some 4,500 families living from it explain why a good piece costs what it costs. Cheap, here, almost always means it is not amber.
