Lau and Murnighan introduced the "faultline" concept into the group diversity literature. Faultlines are "hypothetical dividing lines that may split a group into subgroups based on one or more attributes." Faultlines result from the pattern, not just the dispersion, of attributes among group members. Measures using dispersion indices do not capture faultline potential. This article reports the development of faultline measures and the characteristics of these measures in two samples.