Provides a visual guide to the internal features of different varieties of beryl.

Fiber-optic illumination reveals rectilinear zigzag-patterned films with vibrant colors in a blue sapphire.

Trigons and tetragons observed in a chameleon diamond indicate both octahedral and cubic growth.

Explores eclogitic diamonds, which make up a significant portion of the gem diamond market, and what they reveal about Earth’s dynamic processes.

Details the colors and optical effects caused by metallic copper inclusions in this gem-quality feldspar.

Reports on the geological setting and gemological properties of violet-blue gem cordierite from new deposits located in British Columbia.

Examines dissolution features of heliodor and green beryl from a Ukrainian pegmatite field and offers criteria to distinguish them from samples found in other localities.