When sourcing random stone, the primary focus should be on mineral composition and water absorption rates. For natural stone, ensure a water absorption rate of less than 0.5% to prevent cracking in freeze-thaw cycles. For 'Random' patterns, verify the thickness consistency (typically 20mm to 50mm) to ensure ease of installation. Always request ASTM or EN standard test reports for compressive strength and abrasion resistance, especially if the stone is intended for high-traffic flooring or external cladding.