The discussion about whether to write «Halde» or «Haldde» has been going on for many years, and there are many emotions attached to this local place name. As with many other places in Finnmark, the name is influenced by several languages, such as Norwegian, Kven and Sami.
According to the Language Council, there are no historical sources that document the use of the spelling «Haldde» with two d's. This suggests that the form has arisen through use over time, without any solid basis in written sources. Because of this, the Language Council has recommended that «Haldde» be discontinued.
Nevertheless, the spelling with two d's has been used extensively in books, including by recognised historians such as Arvid Petterson and physics professor Alv Egeland. They haven't necessarily considered where this spelling originated. Even Alta Museum has previously used «Haldde», but they have now changed their practice and follow official recommendations by using «Halde» with one d.
Over the past few years, place names in Finnmark have been scrutinised with the involvement of the Language Council, the Sami Parliament and the Norwegian Mapping Authority. Today, there are four approved names for the mountain peak: Halde, Vuoranšnjárggaháldi, Háldi and the perhaps more well-known Sukkertoppen.
Which spelling is correct?
The Norwegian Mapping Authority has determined that «Halde» is the correct Norwegian spelling, while «Háldi» is the recognised form in Northern Sami. «Haldde» is not an official spelling in either Norwegian or Sami. The North Sámi word «háldi» means «guardian spirit», and it is probably this word that has given rise to the place name.
The Norsk stadnamnleksikon describes «Háldi» as a mountain name used in several places, including Finnmark and northern Finland, and it can mean both «guardian spirit» and in some cases «underground being».
Conclusion
If you want to be correct, the mountain should be written «Halde». In addition, you can use the Sami and Kven alternatives Vuoranšnjárggaháldi, Háldi or Sukkertoppen, depending on the context.
Sources:
Alta Museum
Language Council
Sami Parliament
Store norske leksikon
Norwegian city name encyclopaedia