gems, spinel, inclusions

Spinel commonly contains angular octahedral crystals, which can occur in neat rows forming delicate fingerprint inclusions. A Vietnamese spinel examined in the laboratory showed a different fingerprint appearance, consisting of a partially healed fissure with a maze-like pattern visible under darkfield illumination. With additional diffuse fiber-optic illumination, small angular areas within the channels appeared highly reflective. This unusual inclusion scene illustrates the variety of patterns that can be observed in spinel.