Lotus • Articles from Lotus Gemology

Some yellow sapphires contain unstable color centers. The following discussion outlines case studies of stones that faded after testing in the lab, and how color may be restored.

Detection of heat treatment below 1200°C in ruby and sapphire can present challenges to gemologists. In this study, the authors heated Burmese ruby samples and detailed the features that help in the detection of heat treatment.

Meet the Extraordinary 40 • Richard Hughes Honored by Jewellery News Asia

Short-wave fluorescent illumination provides a useful tool to spot curved banding in flame-fusion synthetic sapphire.

Blue apatite crystals in garnet.

An apatite crystal appears to float, suspended over a rutile silk cloud in a star sapphire.

Oil treatment has a significant impact on the appearance of an apatite.

Hogbomite-filled dislocations in a Vietnamese spinel.

A web-like fingerprint creates a maze-like pattern in spinel.

The internal world never fails to amaze, as witnessed by this incredible video of a negative crystal in a Sri Lanka sapphire.