When plain tortoise-shell combs are defaced, the polish may be removed by rubbing them with pulverized rotten-stone and oil. The rotten-stone should be sifted through muslin; then polish with jeweller’s rouge, or with sifted magnesia.
Meanings of Word or Phrases used
Jeweller’s rouge – Red powdered haematite, iron(III) oxide. It is a mild abrasive used in metal cleaners and polishes.