A kind of kohl. There can be six types of añjana (anjana): sauvīra (sauvira), yāmuna (yaamuna), tuttha, mayūragrīvaka (mayuragrivaka), darvikā (darvika) and meghanīla (meghanila) —
sauvīraṃ yāmunaṃ tutthaṃ mayūra-yāmunaṃ tathā/ darvikā meghanīlaśca añjanani bhavanti ṣaṭ.
Ayurveda has use of all these six types of kohl.
Sauvīra is the sap of a plant; yāmuna, a certain stone; meghanīla, a metallic element; and mayūragrīvaka, a gemstone. Kohl is produced by crushing them on stone or metal vessels. The kohl produced by heating the ghee/oil-smeared inside of a copper vessel on a flame is called darvikā —
Ghṛtatailādiyogena tāmrādau dīpabahṇinā/ yadañjanaṃ jāyate sā tu darvikā parikīrtitā.
Amongst these, tuttha deserves separate mention. It has been observed, “copper in combination with the burning water gives rise to ‘tuttha’ (blue vitriol).” And there is another opinion that the kohl made by mixing sea-foam, powdered haritaki fruit (Terminalia chebula) and tuttha or copper sulphate is a sure remedy for a certain type of eye disease.