OREAS 471

OREAS 471 is a clay-hosted rare earth element (REE) certified reference material produced from a blend of kaolin, REE-enriched ultra-fine milled products, siltstone, and high-purity silica. It is designed to support the calibration and quality control of geochemical methods targeting total rare-earth and yttrium oxides (TRYEO). The matrix closely replicates the mineralogy of ionic-adsorption clays found in critical REE deposits. This CRM is part of the Critica Jupiter – Clay-hosted REE CRM suite, developed to support exploration and metallurgical assessment of REE-bearing lateritic and weathered systems.

OREAS 471 has been characterized for REE suite using the following methods:

• Borate Fusion XRF litho / silicate rock package – majors
• Thermogravimetric LOI at 1000 °C
• Borate/Peroxide Fusion – Full ICP-OES and MS elemental suites
• 4-Acid – Full ICP-OES and MS elemental suites
  Ammonium sulphate leach – REE’s

Certified values for applicable analytes are operationally defined for each method, with results under OREAS ISO 17034 scope of accreditation.