Island

An island is a piece of land that is surrounded by a body of water such as a lake, river, sea or ocean. Islands are smaller than continents. Although there are many Islands that are surrounded by fresh water, the vast majority of them are surrounded by oceans.

Greenland and Australia are huge islands, but they are built of continental rock, and the latter is generally considered a continent. The most ancient part of continental rock is far older and chemically more complex than the rock of the sea floor. 

The heart of continents is their cratons, which are the most ancient and stable parts of the Earth's crust. In the cratons are all the rare elements needed for electronic equipment. They were swept up as the Sun moved through areas where supernovae had exploded. The rare elements we need were all got indirectly from supernovae explosions. The Sun's energy  comes from turning hydrogen into helium.

There are some islands which do have rare elements, and that is a sign that they were once part of a large supercontinent. So Great Britain was once part of a supercontinent. The oldest rocks are 2,700 million years old, and include many rare elements only found in cratons.Toghill, Peter 2000. The geology of Britain: an introduction. Shrewsbury: Swan Hill Press. ISBN 1-85310-890-1 Britain is a snapped-off piece of the Old Red Sandstone continent, now known as Laurasia.

Other islands that were formed from the ocean floor, as Japan, and Hawaii were, lack most of the rare elements. Japan has for many years since WWII imported iron ore from Australia. Its seizing of Manchukuo (~Manchuria) and the infamous attack on Pearl Harbour no doubt had many reasons. Lack of raw materials was one of these Yamamuro, Shin'ichi. 2006. Manchuria under Japanese dominion. U. of Pennsylvania Press. Now it looks  for potential in its nearby deep-sea muds.Takaya, Yutaro 2018. The tremendous potential of deep-sea mud as a source of rare-earth elements. Nature. 8 (1): 5763.  doi:10.1038/s41598-018-23948-5. PMC 5893572. PMID 29636486.


 Big islands 
 In Europe 
 Great Britain 218,995 km²
 Iceland 101,826 km²
 Ireland 81,638 km²
 The island in the north of Novaja Zemlja 47,079 km²
 Spitsbergen 38,981 km²
 The island in the south of Novaja Zemlja 33,246 km²
 Sicily 25,662 km²
 Sardinia 23,812 km²
 Nordaustlandet (archipelago of Svalbard, Norway) 14,247 km²
 Corsica 8,741 km²

 Other places 
 Australia 7,662,000 km²
Cyprus 9,234 km²
 Greenland 2,130,800 km²
 New Guinea 785,753 km²
 Borneo 748,138 km²
 Madagascar 587,041 km²
 Baffin 507,451 km²
 Sumatra 442,658 km²
 Honshu 233,000 km2
 Victoria Island 217,000 km2
 Ellesmere Island 196,000 km2
 wsp 

References

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