Demantoid, Andradite, and Grossular from Mexico
A look at new gem material from the iridescent andradite deposit in Sonora, Mexico.
Pyritized Triceratops Fossils from South Dakota
A newfound dinosaur site in the Hell Creek Formation of South Dakota leads to the discovery of pyritized triceratops fossils.
“Kaleidoscope” in Alexandrite
Pleochroic colors caused by cyclic twinning produce a kaleidoscope effect in alexandrite.
Pseudo-Icosahedral Pyrite in Colombian Emerald
A 2.88 ct Colombian emerald plays host to a metallic yellow pyrite crystal.
Yellow Radiation Halos in Iolite (Cordierite)
Zircon, monazite, and apatite inclusions surrounded by yellow halos are observed in an iolite cabochon.
Rock Crystal with Cross Inclusion Exhibiting Brownian Motion
Numerous two-phase inclusions form a cross in a rock crystal pendant.
Spiky Inclusion in Padparadscha Sapphire
An inclusion with a metallic luster is observed in a pinkish orange padparadscha sapphire.
