Note: 1. Avoid contact with hydrofluoric acid. 2. Do not heat or place in the oven to dry. 3. Large pieces or lumps of samples must be crushed externally before grinding in the agate mortar. 4. Clean the mortar with water after use; if necessary, use dilute hydrochloric acid followed by rinsing with water. For stubborn residue, add a small amount of salt to grind, then rinse. Sea sand can be substituted for salt if needed. 5. Do not grind objects with high hardness or coarse particles to prevent surface damage. 6. When grinding, place the mortar on a stable surface and keep it upright. Large solids should be crushed, not ground, to avoid damage to the mortar or solids. Lightly crush explosive substances; do not grind. For corrosive materials, cover the mortar with thick paper or plastic, creating a hole for the pestle before grinding. Do not exceed 1/3 of the mortar's capacity with solids. Product Details: Product Name: Natural Agate Mortar. Material: Agate. Main Use: Grinding. Shape: Arc. Specifications: 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm.