- Siglo Veinte Mine (Siglo XX Mine; Llallagua Mine; Catavi), Llallagua, Rafael Bustillo Province, Potosi Department, Bolivia
- Small Cabinet, 6.0 x 5.5 x 3.3 cm
Monazite gets its name from the Greek word "monazein," which means "to be alone," in allusion to its isolated crystals and their rarity when first found. Monazite is usually found in granitic pegmatites, but these crystals are found in hydrothermal tin veins where there is an absolute absence of Thorium (usually a trace element in Monazite). This is a remarkable, very well crystallized, very rare, specimen consisting of sharp, lustrous, translucent, orange-pink, twinned crystals of Monazite-(Ce) measuring up to 7 mm on Quartz crystals on matrix. The crystals actually perform a color change in different lighting ranging from orange-pink to a white/yellow (more pink in sunlight and more yellow in fluorescent light). This piece is from the same mine for which this material was discovered along the Contacto and San Jose veins in this mine and was first described by Sam Gordon and Mark Bandy.