Gem Testing • Gemology Books, Articles from Lotus Gemology

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

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.

Blue apatite crystals in garnet.

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

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.

A truth that's told with bad intent, beats all the lies you can invent.

—William Blake [1757–1827], Proverbs, Line 95