Agate natural quartz stone pestle and mortar, non-porous extremely hard single piece natural stone for long lasting durability. This pestle and mortar has a highly polished interiour surface, makes for simple crushing and mixing of materials and easy cleaning. Ideal for labs which use a large variety of materials. Available in a variety of sizes to fit with needs. Suggest using the 3 inch mortar variant for under 2 g, 4 inch mortar for 1-5 g and 6 inch mortar for larger volumes of powders. Diameters given and outer diameter.