Purple Wool Coat and Featherd Hat

This look is made up of a collarless coat with slit pockets and hat of purple wool; the coat has a strongly asymmmetrical buttoning, while the hat is trimmed with purple and hot pink feathers. The matching silk dress sports a pink carnation print on a dark (black?) background.
As far as I'm aware, this look has been worn with the Kent amethyst brooch, whose colour is a perfect match for the purple coat, on all occasions bar one.
It was first worn on 11 March 2010, for a visit to Wyvern Barracks in Exeter, which were hosting the Devon Cadet 150 celebrations to mark 150 years of the Cadet movement:

 

A few months later, on 21 October 2010, the Queen repeated this look for a visit to Northern Ireland, during which she toured the UTV Studios in Belfast and launched their new high-definition television channel:

 

During the tour, the Queen even made a 'guest appearance' on the weather forecast:

On 8 December 2010, the Queen was once again pretty in purple on a visit St Mary and St Pancras Church of England Primary School in Camden, London, where she was presented with a bouquet of what looks like tissue paper blooms:

On 6 February 2011, the 59th anniversary of her accession to the throne, the Queen attended a morning service at West Newton Parish Church, accompanied by the Duke of Edinburgh.

 

You can see from the photo below that the hat is lined in the same silk fabric as the coat:

Almost a year later, on 8 December 2011, the Queen repeated this look on a visit to the Dedworth Medical Centre in Windsor and later for the opening of the Windsor and Royal Borough Museum in the Guildhall. This is the only occasion I'm aware of when the Queen didn't wear her Kent amethysts with her coat, choosing instead her six-pointed diamond flower brooch:

 

After a long spell hidden in the royal closet, the outfit saw the light again on 29 December 2013, for Sunday church at Sandringham:

After another long spell out of the public eye, on 12 May 2015, the Queen repeated once again this look to attend a memorial service for the eighth Duke of Wellington at the Guards Chapel on Birdcage Walk, Westminster. It is unusual for the Queen to attend funerals or memorial services for non-relatives, but she made an exception for the Duke of Wellington, who was a Knight of the Garter and the holder of one of the most historically illustrious titles in the British peerage. Another outing for the Kent Amethyst brooch, as well:

 

About seven months later, on 3 January 2016, the look reappeared, worn for Sunday Church at St Mary Magadalene on the Sandringham estate (Daily Mail article here). As usual with this sort of engagements, difficult to tell exactly which brooch the Queen wore, although I suspect the Kent Amethyst might be a serious contender: