Fostering Circularity in the Stone Industry: Multi-Criteria Analysis of Existing Sustainable Indicators for Decision-Making Support

The stone industry generates substantial waste along the quarrying, cutting and finishing chain, with only about 22% of the extracted material processed into final products, while roughly 64% is lost as slurry and 8% as solid waste. Compared to other industries such as wood and steel, there is a significant gap in the exploitation of relevant circular economy indicators for the stone industry. To address such limitation, this study proposes a sector-specific indicator framework built in three stages: systematic identification of existing CE indicators through a Scopus-based literature review, further refinement against three strategies for the stone sector (materials preservation, process optimisation and reduction of risk to human well-being), together with two suitability filters based on development stage and redundancy, and finally an indicative prioritisation using a simplified Analytic Hierarchy Process (AHP) procedure implemented in Super Decisions. Seven indicators are retained as the most applicable to the sector: Energy Use, Water Consumption, Greenhouse Gas Emissions, Replacement Ratio, Generation Ratio, Upcycling Score and Product Quality Index. The Consistency Ratio is 0.070 for the criteria pairwise-comparison matrix and ranges from 0.000 to 0.010 across the six indicator pairwise-comparison matrices, reflecting the internal coherence of the deterministic scoring procedure used to derive them. The framework is presented as an initial, transparent proposal to support monitoring and resource efficiency benchmarking in the stone supply chain. Empirical validation through further industrial case studies and broader expert contribution is an essential next step.