Particular specification: * Fe 3 content (%): ≥ 95 * Reduction (contrast with standard): da -0.5~0.5; dB -0.5~0.5 * Tinting strength(contrast with standard): 98-105 * Volatiles under 105: ≤ 1.0 * Water soluble matter(%): ≤ 0.5 * PH of aqueous eztract solution: 5~8 * Oil absorption (g/100g): 15~25 * Residue on sieve 45un(%): ≤ 0.10 * Productivity: 6500 T/year