It is stated that sandstones weather differently.
Some sandstones are stronger than others due to a quartz cement.
After burial groundwater moving through the sand grains will dissolve some of the silica from the loose quartz particles. Later, after further burial, this solution of silica rich water will deposit silica cement around the grains bonding one grain to another. This process acts to turn the aggregate into a rock called a sandstone. This process is called diagenesis. Likewise salt has been in use for the same length of time.