The Collaborative International Dictionary
Jewstone
Jew's-stone \Jew's-stone`\, Jewstone \Jew"stone`\, n. (Paleon.) A large clavate spine of a fossil sea urchin.
Wiktionary
jewstone
alt. A fossil of a spine of a sea urchin, once used in the Middle East as a medicine n. A fossil of a spine of a sea urchin, once used in the Middle East as a medicine