- Siglo Veinte Mine (Siglo XX Mine; Llallagua Mine; Catavi), Llallagua, Rafael Bustillo Province, Potosi Department, Bolivia
- Miniature, 3.2 x 3.1 x 2.2 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 is an absolute absence of Thorium (usually a trace element in Monazite). This is a remarkable, very well crystallized, ridiculously rare, specimen consisting of sharp, lustrous, translucent, orange-pink, twinned crystals on Monazite-(Ce) measuring up to 7 mm on Quartz crystal matrix. These twins are some of the most distinct and impressive twinned Monazite crystals I have seen from Bolivia. The crystals actually perform a color change in different lighting ranging from orange-pink to almost colorless depending upon the light source. This specimen has some of the largest crystals I have seen from this mine, and this piece just came out of the ground a few months ago! It is very difficult to obtain any specimens of this incredibly beautiful and rare phosphate, especially in crystals from Bolivia like this. 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. It is so unbelievably rare to find matrix specimens of Monazite-(Ce) from any locality in Bolivia or anywhere else in the world. This species is often dark and opaque from most localities and rarely bright like these. These crystals also do a color change from indoor lighting to sunlight (more pink indoors). Ex. Brian Kosnar.