Minette is a type of mineral deposit, consisting of iron ore of sedimentary origin, found in the south of Luxembourg and in Lorraine.
The phosphorus content of Minette rendered its industrial processing impossible for a long time, which changed with the introduction of the Thomas-Gilchrist procedure.
[3] Although the German authorities awarded significantly more mining concessions than the French had, iron ore production hardly increased until 1879.
This changed in the 1880s, due to a greater number of railway lines in the Minette area and the construction of a railway line from Thionville in France to Völklingen in Germany, which from 1883 enabled a direct link with the Saarland industrial area.
[3][4] Explorations in the 1880s showed that the Minette reserves reached further to the West than had previously been assumed, and increased in volume and iron content the deeper they went.