Exploration Standards for Gemstones, Rare Metals, and REEs Updated Minerals (Evidence of Mineral Contents) Amendment Rules, 2025 dated 12.06.2025 sets uniform exploration standards for gemstones, rare metals, and REE deposits, ensuring systematic assessment from initial survey to detailed exploration for accurate resource estimation." The amendment updates Schedule-I, the exploration norms and guidelines for the following categories of mineral deposits: 1. Gemstones (e.g., beryl, topaz, emerald, diamond, fluorite in carbonatite): Stage Exploration Requirement G4 Scout drilling (as needed); 8–10 pits/trenches per sq.km G3 Boreholes to test continuity at 200m or closer; Trenching preferably at 50m intervals G2 Boreholes at 100–50m or closer G1 Borehole spacing may be even closer than G2; exploratory mine openings (open pit/underground) with bulk sampling for grade and recovery analysis 2. Rare Metals and Rare Earth Elements (REEs) in Pegmatites, Reefs, Veins, Pipes: Stage Exploration Requirement G4 Scout drilling, random pitting/trenching as required G3 10–25 pits/trenches per sq.km; drilling at 40m × 20m or 40m × 40m G2 Trenching at 20m intervals; drilling at 20m × 10m or 20m × 20m G1 Open pit or underground sampling; boreholes at 10m × 10m or closer with bulk determination of grade and recovery 3. Rare Metals and REEs in Carbonatite and Alkali Igneous Rocks: Stage Exploration Requirement G4 & G3 Scout drilling, random pitting/trenching as per necessity G2 Borehole/sample spacing at 400m × 200m or closer G1 Spacing reduced progressively to 100m × 100m or closer