Alnö ("the aln-ey") is an island in the Gulf of Bothnia just outside Sundsvall in

Medelpad Medelpad ( or ) is a historical province or ''landskap'' in the north of Sweden. It borders Hälsingland, Härjedalen, Jämtland, Ångermanland and the Gulf of Bothnia. The province is a part of Norrland and as such considered to be Northern ...

, Sweden. It has an area of 67.79 km² and a permanent population of 8,417 (as of 31 December 2010), although its summertime inhabitants are about twice that number. Most of the island's inhabitants work in Sundsvall and other towns on the mainland. The island is 15 km long and 6 km wide on the widest spot. It is connected to the mainland by a bridge, which was the longest bridge in Sweden when it was opened in 1964. Evidences of habitation on the island predate the

Viking Age The Viking Age () was the period during the Middle Ages when Norsemen known as Vikings undertook large-scale raiding, colonizing, conquest, and trading throughout Europe and reached North America. It followed the Migration Period and the Germ ...

, and there are several

tumuli A tumulus (plural tumuli) is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds or ''kurgans'', and may be found throughout much of the world. A cairn, which is a mound of stones built ...

on the island from that period. The old stone church near the modern bridge was built in the 12th century. The island saw a population boom in the second half of the 19th century, due to the development of steam-driven

sawmill A sawmill (saw mill, saw-mill) or lumber mill is a facility where logs are cut into lumber. Modern sawmills use a motorized saw to cut logs lengthwise to make long pieces, and crosswise to length depending on standard or custom sizes (dimensi ...

s. In 1850 the island had 950 inhabitants, mainly farmers and fishermen, but by 1900 the population had grown to almost 7,000, following the establishment of 18 sawmills between 1860 and 1897. As result of decreased foreign trade during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

apatite was mined in Alnön from 1943 to 1945. Aparite was separated by flotation but results were meagers. While the separation process had improved in 1945 the end of the war the same year ment also apatite mining became unproffitable.

Geology

Alnö was affected some 570 million years ago by a massive

volcanic eruption Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are oft ...

. The northeastern part of the island is rich in

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate ...

minerals, and it is one of few areas in the world with a

carbonatite Carbonatite () is a type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals. Carbonatites may be confused with marble and may require geochemical verification. Carbonati ...

volcanic complex. Its chemistry is very different from the ordinary granitic rock that form the rest of the island, resulting in a number of unusual minerals, such as baryte and

aegirine Aegirine is a member of the clino pyroxene group of inosilicate minerals. Aegirine is the sodium endmember of the aegirine-augite series. Aegirine has the chemical formula Na Fe Si2 O6 in which the iron is present as Fe3+. In the aegirine-augit ...

. The most famous of the

rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

s of Alnön is the ''alnoite'', named from the Island, which is a

lamprophyre Lamprophyres () are uncommon, small-volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks, and small intrusions. They are alkaline silica- undersaturated mafic or ultramafic rocks with high magnesium ...

chiefly composed of biotite or

phlogopite Phlogopite is a yellow, greenish, or reddish-brown member of the mica family of phyllosilicates. It is also known as magnesium mica. Phlogopite is the magnesium endmember of the biotite solid solution series, with the chemical formula KMg3AlSi3O ...

and

melilite Melilite refers to a mineral of the melilite group. Minerals of the group are solid solutions of several endmembers, the most important of which are gehlenite and åkermanite. A generalized formula for common melilite is ( Ca, Na)2( Al, Mg, ...

as essential minerals, commonly with

olivine The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...

, calcite and

clinopyroxene The pyroxenes (commonly abbreviated to ''Px'') are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents calcium (Ca), sodium (Na), iron (Fe I ...

Perovskite Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as (XIIA2+VIB4+X2−3), known a ...

, apatite,

nepheline Nepheline, also called nephelite (), is a rock-forming mineral in the feldspathoid groupa silica-undersaturated aluminosilicate, Na3 K Al4 Si4 O16, that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatite ...

and

garnet Garnets () are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms, but differ in chemical composition. The different s ...

may also be present.

Diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, ...

s have also been found on Alnön, but only in very small amounts. Alnöbron

Sport

Alnö IF Alnö IF is a Swedish football club located in Alnö, just outside Sundsvall in Medelpad. Background Alnö Idrottsförening was formed on 24 April 1924 at the Hammarstedts Cafe in Vii. The sports club has been active in skiing, wrestling, box ...

Notable citizens

* Vilma Abrahamsson, Football player *

Gunnar Hellström Gunnar Hellström (6 December 1928 – 28 November 2001) was a Swedish actor and director. Partial filmography * ''While the City Sleeps'' (1950) - Young Man in Restaurant * '' U-Boat 39'' (1952) - Harriet's Escort * '' She Came Like the Wind ...

, Director *

Tina Nordlund Tina Cecilia Elisabeth Nordlund (born 19 March 1977) is a Swedish football coach and former player, most recently an assistant coach at Umeå IK. She is one of the most well known Swedish female footballers. In November 2000, she was awarded th ...

, Football player *

Hjördis Schymberg Hjördis Gunborg Schymberg (April 24, 1909 – September 8, 2008) was a Swedish coloratura and lyric soprano active on the opera stage and in concert halls between 1934 and 1968. One of the leading singers of the Royal Swedish Opera, she was aw ...

, Opera singer * Andreas Yngvesson, Football player *

Helen Sjöholm Marie Helen Sjöholm (; born 10 July 1970) is a Swedish singer, actress and musical theatre performer who lives in Gamla Enskede in Stockholm. She grew up in Sundsvall and started to sing in choirs at an early age, working, among others, with S ...

, Singer and actress

References

External links

Rock samples from Alnön
{{DEFAULTSORT:Alnon Sundsvall Municipality Islands of Västernorrland County