TS ISO 7404-1

TS ISO 7404-1 defines the common technical language used in the petrographic analysis of bituminous coal and anthracite. This part clarifies the terms applied in maceral and microlithotype analysis, including observations carried out in white light and the determination of vitrinite reflectance, so that results from the same coal sample can be described and interpreted more consistently.

Why terminology matters in coal petrography

Coal petrography examines the microscopic constituents and texture of coal to help describe rank, compositional variability, and behaviour in use. In this field, macerals are the organic constituents of coal, while microlithotypes describe their combined appearance at the microscopic level. Vitrinite reflectance is a key parameter for interpreting coal rank and maturation. TS ISO 7404-1 supports this work by defining how these concepts are named and understood, helping laboratories, researchers, and industry specialists use the same technical vocabulary.

What this part covers

• Terms used in maceral analysis performed in white light
• Terms used in microlithotype analysis performed in white light
• Terms associated with the determination of vitrinite reflectance
• Shared vocabulary for petrographic assessment of bituminous coal and anthracite

This document is a vocabulary part rather than a testing method standard. Its value lies in terminology control: it helps ensure that descriptions, reports, and comparisons refer to the same concepts, instead of relying on loosely interpreted wording. As an edition based on ISO 7404-1:1994 and later withdrawn, it remains a useful technical reference for understanding the terminology used in coal petrography.