Geochemistry

Geochemistry determines the elemental composition of rocks, minerals and ores through systematic chemical analysis, building large comparative datasets that let a sample's composition be matched against known sources rather than described only by appearance. Frank Wigglesworth Clarke, chief chemist of the United States Geological Survey, gave the discipline its foundational reference in 1908 with The Data of Geochemistry, a compilation of essentially every reliable chemical rock and mineral analysis then available, organized so a composition could for the first time be compared systematically across a large body of prior work rather than against a handful of scattered individual studies.

Sacred architecture and ritual objects, stone for a temple, pigment for an icon, metal for a cast image, carry a specific chemical signature tied to where their raw material actually came from, and geochemical analysis can trace that signature back to a source quarry or mine independent of any tradition's own account of the material's origin. The atlas draws on geochemistry wherever a sacred site's construction material or a ritual object's metal content is used to check a claimed origin or date, particularly where a tradition claims a material traveled an unusually long distance to reach its sanctuary.