ISO 6868:2026

This document specifies three methods for quantitative measurement of crystalline silica (CS) major polymorphs (quartz and cristobalite) mass percentage content in bulk samples using X-ray powder diffraction (XRPD). This document also provides general information about the capabilities and limitations of relevance to laboratories working for routine testing.
Only X-ray diffractometers with Bragg-Brentano geometry are considered. XRPD techniques are used to characterize specimens in the form of loose powders, where the median grain size is between 1 μm and 10 μm physical diameter. Block specimens are not considered.
Although a number of methods of analysis are considered in this document, other XRPD methods of analysis can be considered if they are demonstrated to give equivalent results.