If they do not break on impact, both a glass and a steel ball of similar proportion to a rubber ball will bounce higher than the rubber ball. – WTF Fun Facts
Source: https://sciencenotes.org/why-a-glass-ball-bounces-higher-than-a-rubber-ball/
steel
WTF Fun Fact – Tooth Enamel
Your tooth enamel is harder than a lobster’s shell or a rhino’s horn. It’s even harder than steel. It’s made of mineralized calcium phosphate, which is the hardest substance a living being can produce. – WTF Fun Facts
Source: https://en.wikipedia.org/wiki/Tooth_enamel