Baikalite sharpening stones are used for finish sharpening and honing knives on Hapstone Pro and Edge Pro sharpeners. Baikalite is a naturally abrasive material of high density. Baikalite stones are mounted on high quality aluminum blanks.Baikalite is mined in the Baikal region of Russia. Baikalite is a dense, opaque variery of silica rock.Specification Product size: 160 x 25 x 9 mm (6" x 1" x ⅓") Working surface: 152 x 25 x 6 mm (6" x 1" x ¼") Weight: 100 g (3.5 oz) Abrasive: Cryptocrystalline Silica Extra materials: Aluminum Blank, 3M PSA How to useBaikalite stones should be used with one of these lubricants: Refined olive oil Oleic aсid Baikalite stones do not have any minor defects. Baikalite stones always have a color pattern; this is not a defect.Baikalite stone does not require any preparations. It is naturally lapped to ultra-fine grit. This is a big advantage because the difficulty of lapping Baikalite is very high.