The phrase "salt of the earth" is being used in various contexts, including a 1954 film, a 2014 film, and a song by The Rolling Stones. It is also being referenced in connection with geological formations, such as underground salt caverns, and in the names of organizations, including a ministry and a solidarity network. The phrase appears to be being used to convey a sense of value or importance, but its specific meaning and application vary widely across different outlets and topics.