Monazite-(Ce) Crystal — Minas Gerais, Brazil

Minas Gerais is one of the world's great mineralogical addresses: a Brazilian state underlain by Archean and Neoproterozoic basement intruded by thousands of granitic pegmatites that have produced gem-quality tourmalines, aquamarine, emerald, topaz, and an exceptional suite of rare earth and phosphate minerals. Monazite is one of its enduring contributions to the collector world. The pegmatites of Minas Gerais — particularly those of the eastern Brazilian pegmatite province near Araçuaí and Governador Valadares and the famous Jaguaraçu district — are recognized internationally for producing some of the finest and best-studied monazite crystals in existence, with individual crystals reaching several centimetres in well-terminated prismatic form. Monazite-(Ce) is a rare earth phosphate, (Ce,La,Nd,Th)PO₄, in which cerium is the dominant rare earth element at the A-site but where lanthanum, neodymium, and other light REEs substitute freely. The mineral forms in granitic and syenitic pegmatites as a primary crystallization product, concentrating rare earths and thorium that do not easily fit into the major rock-forming silicates. The thorium content is responsible for the mineral's mild to moderate radioactivity, and in high-thorium specimens the crystal structure is frequently metamict — progressively disordered by sustained alpha radiation over geological time — though Minas Gerais examples often retain excellent external crystal form. Colour ranges from reddish-brown to honey-yellow, with a resinous to vitreous lustre and good hardness; well-crystallized specimens are among the most aesthetically appealing of the radioactive phosphate minerals. Monazite plays a significant role in both geochronology and industrial rare earth extraction: its U-Th-Pb system is used to date geological events with precision, and it is a major feedstock for the global rare earth supply chain. A well-formed crystal from Minas Gerais bridges the gap between geological science, industrial significance, and collector appeal in a single specimen. Mildly radioactive. Canada domestic shipping only. Approx. specimen size: 30mm x 30mm x 15mm Approx. specimen weight: 32.17 grams Approx. specimen activity on an SE International Ranger EXP: 1500 CPM