a1400 618/222 Iewes ston-hard in sinnes merk.
c1400 (?c1380) l. 884 & steken þe ȝates ston-harde wyth stalworth barrez.
a1616 W. Shakespeare (1623) iv. iv. 221 + 7 The murd'rous Knife was dull and blunt, Till it was whetted on thy stone-hard heart.
1875 Ld. Tennyson i. v. 48 He is..Stone-hard, ice-cold—no dash of daring in him.