Reviews
1.85" Botryoidal Hyalite Opal with Chalcedony - Mexico
This 1.85" wide specimen features an association of glassy botryoidal hyalite opal and chalcedony, collected from San Luis Potosi, Mexico. Portions of this specimen exhibit faint wgreen fluorescence under shortwave UV light. The reaction to shortwave UV is a result of trace uranyl ions.
About Hyalite Opal
Hyalite is a transparent to translucent variety of opal that commonly forms smooth, glassy globules or botryoidal coatings. An amorphous form of silica (SiO₂), hyalite is classified as a mineraloid and typically forms as a volcanic sublimate in volcanic or pegmatitic environments, where silica-rich vapors condense and solidify. It is also known as water opal, jalite, or Müller’s glass, named after its describer, Franz-Joseph Müller von Reichenstein.
One of hyalite’s most distinctive features is its intense fluorescence: under shortwave ultraviolet light, many specimens glow a vivid neon green. This striking effect is caused by trace amounts of uranium, present as uranyl ions, incorporated into the opal’s structure during formation. In normal lighting, hyalite often appears colorless and glass-like, making its dramatic UV response especially surprising and highly prized by mineral collectors.
Hyalite is a transparent to translucent variety of opal that commonly forms smooth, glassy globules or botryoidal coatings. An amorphous form of silica (SiO₂), hyalite is classified as a mineraloid and typically forms as a volcanic sublimate in volcanic or pegmatitic environments, where silica-rich vapors condense and solidify. It is also known as water opal, jalite, or Müller’s glass, named after its describer, Franz-Joseph Müller von Reichenstein.
One of hyalite’s most distinctive features is its intense fluorescence: under shortwave ultraviolet light, many specimens glow a vivid neon green. This striking effect is caused by trace amounts of uranium, present as uranyl ions, incorporated into the opal’s structure during formation. In normal lighting, hyalite often appears colorless and glass-like, making its dramatic UV response especially surprising and highly prized by mineral collectors.
$19
SPECIES
Opal var. Hyalite & Quartz var. Chalcedony
LOCATION
San Luis Potosi, Mexico
SIZE
1.85 x 1.5"
CATEGORY
SUB CATEGORY
ITEM
#324369
