EntityQ1482030· pop 30· linked from 30 articlestouchstoneSign in to savesmall tablet of dark stone used for assaying precious metal alloysConnectionsgoldEntitymetalEntityAncient GreeceEntityInternational Standard Book NumberEntityalloyEntityIndus Valley CivilizationEntitydigital object identifierEntityInternational Standard Serial NumberEntitynitric acidEntityaqua regiaEntitybibcodeEntitylitmusEntityopen accessEntityslateEntitystreakEntityprecious metalEntityfinenessEntityradiolariteEntityMetallurgical assayEntityTouchstoneEntityCategoriesGoldIndian inventionsInventions of the Indus Valley CivilisationJewelleryLithicsMaterials science