Editing Evje og Hornnes (section)

==Geology==
The Evje og Hornnes municipality is situated at the southwestern margin of the [[Baltic Shield]], the exposed section of the [[East European craton]]. Rocks in the area are dominated by different types of precambrian [[gneis]] and a large meta[[gabbro]] body stretching into the neighboring Iveland municipality.

During the final stages of [[Sveconorwegian orogeny|Sveconorwegian]] (0.9–1.1&nbsp;[[gigaannum]]) [[orogeny]], a large [[pluton]] of [[granite|granitic]]/[[Monzonite|monzonitic]] composition was emplaced in the northern part of the municipality and is assumed to have a relationship with the thousands of [[pegmatite]] veins in the Evje-Iveland area.

Earlier during the [[Sveconorwegian orogeny]], [[mafic]] rocks ([[gabbro]]-[[diorite]]) were emplaced. Most of the gabbro has been affected by the Sveconorwegian orogeny and became a metagabbro (amfibolite) with only minor remnants of the original gabbro. The Flåt Nickel Mine is situated at the north-western margin in a diorite intrusion post-dating the gabbro.

The pegmatites of the Evje-Iveland area have become worldwide known for a large number of rare and often crystallized minerals.

The pegmatites were initially mined for [[quartz]], used in the melter at Fennefoss to extract the nickel from the ore from the Flåt Nickel Mine. Later, large quantities of [[feldspar]] were mined for use in the [[ceramic]] industry, both in Norway and abroad. Also [[mica]] ([[muscovite]]), [[beryl]], [[rare-earth]] minerals, [[scandium]] ore, and minor quantities of [[uranium]] ore were mined.

After 1983, almost all mines were abandoned, and nowadays only minor quantities of "tannspat" or dentalspat are mined in a couple of mines. This is [[microcline]] or [[plagioclase]] feldspar of very high purity and used to make [[porcelain]] teeth-fillings or [[dentures]]. The tannspat is exported to [[Germany]], [[Liechtenstein]], [[Austria]], and sometimes [[Japan]].

A number of the mines is still open to mineral collectors.{{citation needed|date=April 2019}}