Scientists have released photographs of what they believe are volcanic glass particles from Iceland which fell on Scotland this week.

The samples were taken from a car windscreen in Aberdeen and analysed at the city's James Hutton Institute.

The images of the tiny particles were taken using a scanning electron microscope.
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© PASharp: One of the fragments of glass that rained on Aberdeen is shown under a microscope

Scientists said it was 'highly likely' the glass particles, which are part of the ash constituents, came from the Grimsvotn volcano which started erupting on Saturday.

Commercial glass is created by heating silica, or sand, to an extremely high temperature. Sand scorched by lava could do the same.

The largest of the particles found is 0.03mm across, with the smallest measuring just 0.002mm wide.

The institute also analysed samples given to them by the Scottish Environment Protection Agency (Sepa) taken in Lerwick, Shetland, which matched the particles taken from the car window.

Evelyne Delbos, the institute's head of electron microscopy, said: 'We analysed the same sample on the same day from Lerwick and it had the same elemental composition.

'It is highly likely the particles came from the Grimsvotn volcano but until we have a reference sample to compare we cannot confirm.'

The ash cloud left hundreds of passengers facing travel misery earlier this week when flights were cancelled as it drifted into Scottish airspace.

Now however, the eruption has subsided and the volcano is producing mostly steam rather than ash and should calm down within a few days, experts say.

Hjalmar Bjorgvinsson, Icelandic national police superintendent, said: 'I hope in a few days it will go to sleep again. Everything is moving in the right direction.'

European air traffic agency Eurocontrol said no airspace was closed due to volcanic ash on Thursday and there was expected to be very little or no impact on European air traffic over the next 48 hours.

The agency said about 900 flights had been cancelled between Monday and Wednesday out of a total 90,000 planned flights over the three days.

The eruption forced cancellations in flights in Scotland, northern England, Germany and parts of Scandinavia.

Geophysicists say the worst appears to be over and that the volcano is not likely to start spewing big amounts of ash again, although volcanoes are extremely unpredictable.

The ash cloud from Grimsvotn -- Iceland's most active volcano - rose as high as 12 miles into the sky after the eruption but gradually fell before disappearing early on Wednesday morning.

Iceland's civil protection and emergency management said there was very little ash or magma coming from the volcano.

'You could say it's almost over, but we cannot declare the eruption as over,' spokesman Rognvalpur Olafsson said.

He said efforts were under way to assist the roughly 1,000 people who have been affected by the fallout from the volcano.

'It's raining in the area now -- since yesterday -- and if you look at the fields they actually appear green because the rain is washing the ash away,' he said.

Last year more than 10 million people were hit by a six-day European airspace shutdown when Eyjafjallajokull erupted, costing airlines more than £1billion.

New procedures put the onus on airlines to make judgments on whether it is safe to fly through ash, in coordination with the forecasting authorities, particularly the Volcanic Ash Advisory Centre at the British Met Office and civil aviation bodies.