Below are values of Young's modulus and Poisson's ratios of some common rocks (Appendix D.1). All the other elastic moduli or constants can be derived from these two using the relations in Appendix D.2. These values are derived from (mostly static) laboratory measurements, and these are normally different from the in-situ values. All rocks show a great variety in elastic properties, in particular when measured in situ. The ‘typical values’ shown below are rounded and are meant as a rough guide. These data on rock properties as measured in the laboratory are derived from tables and information in many books including Jaeger and Cook (1979), Jumikis (1979), Carmichael (1989), Jeremic (1994, for rock salt), Waltham (1994), Hansen (1998), Nilsen and Palmström (2000), Myrvang (2001), Schön (2004), Paterson and Wong (2005), Fjaer et al. (2008), and Mavko et al. (2009). When data are not known, or not measurable (such as the tensile strength of unconsolidated sand or gravel), there is no number in the appropriate box in the tables in Appendices D and E.