The near-eight-year-old mobile geologist has just found slivers of a bright material that looks very much like it is gypsum (hydrated calcium sulphate).
It produces quick-setting cement, by the addition of calcium sulphate, which produces the Microcem brand, known as a special cement.
The result is hydrated to turn the calcium sulphate into the dihydrate gypsum and sold as superphosphate of lime.
An anhydrous form of calcium sulphate (CaSO4), which in nature occurs as beds up to a few metres thick.
Gypsum is the first salt (calcium sulphate) to be deposited from a desiccating basin.
Accumulation of calcium sulphate, with or without carbonates, is concentrated in and below the B-horizon.
A greater problem for scaling is the deposition of calcium sulphate.
The limestone process results in gypsum, calcium sulphate, which can be sold as a building material.
The calcium sulphate was probably concentrated by evaporation of shallow lakes, though wind-borne gypsum dust may have contributed in places.
Gypsum fibrosum is a type of plaster stone containing calcium sulphate and is said to be "cooling by nature".