Geological resistance is a measure of how well mineral

Mineral

A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

s resist erosive factors, and is primarily based on hardness, chemical reactivity and cohesion

Cohesion (chemistry)

Cohesion or cohesive attraction or cohesive force is the action or property of like molecules sticking together, being mutually attractive...

.http://academic.brooklyn.cuny.edu/geology/leveson/core/graphics/nyc_mins2/resistance.html The more hardness, less reactivity and more cohesion a mineral has, the less susceptible it will be to erosion. Differences in geological resistance in the same geological formation can lead, over time, to the formation of columns and arches like the ones in Moab, Utah

Moab, Utah

Moab is a city in Grand County, in eastern Utah, in the western United States. The population was 4,779 at the 2000 census. It is the county seat and largest city in Grand County. Moab hosts a large number of tourists every year, mostly visitors to the nearby Arches and Canyonlands National Parks...

 and bridges like the Rainbow Bridge

Rainbow Bridge

Rainbow Bridge may refer to:Bridges :* Rainbow Bridge National Monument, a natural rock formation located in Utah, USA* Rainbow Bridge , in Kansas* Rainbow Bridge , on the United States – Canada border...

, also in Utah.