The history of Baja California has been closely tied to the exploitation of pearls since the 16th century.

Natural turquoise has been subjected to dyeing and three types of impregnation.

Topaz is an important gemstone that occurs in various colors.

The author examined a 0.56 ct Fancy grayish bluish green diamond with prominent green radiation stains.

Examination of gold bracelet bearing a 14K hallmark reveals a wax or resin material under gold plating.

“Rainbow” andradite from Nara, Japan, occurs as relatively small orangy brown crystals that show attractive iridescence in almost the entire range of the spectrum.

Offers a comprehensive look at a variety of augite from Dong Nai, Vietnam, detailing its formation and gemological characteristics.