Brøgger named this mineral dahllite after Tellef Dahll and his brother Johan who ran mining operations there at the time.

[5] In the mid-1800s, it was discovered that phosphorus, an essential nutrient that many crops lacked, could be used more effectively in fertilizer if sulfuric acid was added to phosphate rocks, creating superphosphate in the process.

A year later, the Dalls field mines opened nearby under the ownership of Kragerø firm named Johan Dahll.

When the Compagnie Française first started mining in 1872, the operations were supervised by director Auguste Daux, who lived in large house nearby that he named Dauxborg.

Delgobe would continue living in Norway until his death in 1916, and by that time he was an influential Norwegian genealogist, civil engineer and vice consul to Belgium.

[10] Though the Dahll brothers' operation was smaller than the Compagnie Française's, employing only 46 men overall, it fared slightly better in the final years of the 19th century.

[11] Apatite samples from the Dahll mine were among the minerals presented as part of Norway's exhibit at the 1876 Centennial Exposition in Philadelphia.

[12] Ødegården Verk was combined into a single operation in 1910, when a consortium led by Håkon Mathiesen bought both mines and resumed production.

With fewer workers to work the fields and an skyrocketing demand for cheap food, farmers had to become more creative, using more agricultural machinery combined with synthetic fertilizers to increase the rate of production.

While the Norwegian government was officially neutral during World War I, they saw the need for increasingly efficient food production, and as such they attempted to run several similar mining and prospecting operations in the district.

Though these plants used a lot of energy, Norway's natural capacity for hydroelectric power made them a very effective substitute for phosphate mining.

As the first part of the study, NGU geologist Jens Hysingjord took samples of several scapolite-bearing rocks in the Bamble area, including some at Ødegården Verk.

Hysingjord noted that the rutile content of the ødegårdite rocks had economic potential, and recommended that more studies be done at the mine site.