Table 3.

Mechanical properties of different cave speleothems^∗∗.

Sample	Elastic Modulus at Max Load (GPa)	Hardness at Max Load (GPa)
Resin	6 ± 0.8	0.08 ± 0.02
Quartz (Zhu et al., 2007)	105 ± 5	13 ± 1
Feldspar (Zhu et al., 2007)	85 ± 5	9 ± 1
Calcite (Ren et al., 2013)	72 ± 11	1.98 ± 0.31
Vaterite (Ren et al., 2013)	39.13 ± 8.04	1.38 ± 0.39
Lake Cave moonmilk	126.4 ± 6.2	17.10 ± 3.2
Lake Cave stalagmite	80.5 ± 3.9	12.86 ± 2.1
Lake Cave stalactite	77.5 ± 5.4	6.2 ± 1.5
Moondyne Cave stalagmite	78.7 ± 3.68	9.1 ± 1.15
Mammoth Cave stalagmite	69.13 ± 5.5	3.5 ± 1.41
Mammoth Cave stalactite	64.39 ± 1.95	3.12 ± 0.8

^∗∗Values are mean ± SD (n = 10).