Dominican Amber (La Toca Fm., 20.43-13.65 Ma)

5.4g piece of amber from the La Cumbre Mine, measuring (mm) 28x24x18. Visible here, is a natural fracture that was infiltrated and completely coated by marcasite during the resin's diagenesis, in a thin film that begins at the rough, unbroken exterior (underside of specimen in picture). There are dozens of visible dual-phase, countless single-phase, and at least two triple-phase bubbles. These are easily seen in the other four related photos of the finished specimen. "Pyrite disease" is a major concern with this specimen; even with preservation in an airtight container, oxidation is still possible, given the presence of gas/liquid inclusions, and the fact that water and gases do penetrate and migrate within amber over time. Portions of the piece may be doomed, but it is interesting while it lasts.