The type of soil in which opals are found.
mechanization means the opal dirt can be removed in bulk
Example sentencesExamples
- Down the slope towards Lightning Ridge, the depth to opal dirt was 65 feet.
- The opal dirt is much harder than on the rest of the field.
- The mine is lighted by electricity and a power plant inside takes opal dirt back to the surface.
- A group of barefooted kids have eyes glued to opal dirt brought up from the mines.
- On the white opal-dirt ridges, you can see the gouger's wives in their cheap flowered cotton pinafores.