Sorting broken glass is rather therapeutic!
First steps
So my first job is to complete the sorting of the glass residues which have all been sieved to retrieve the tiniest fragments. I have about 3kg of these, which were roughly sorted at assessment, but I am now going through them again, so that we can retrieve the maximum amount of information. The unsorted pile looks quite a jumble, but gradually this falls into more ordered heaps. You can see the different glass colours quite easily.
Roman glass was made by heating silica (sand), soda, which was used as a flux to reduce the melting temperature and calcium (lime) which acted as a stabiliser. Iron oxide, a naturally-occurring impurity in the sand produces a the characteristic blue-green shades of much Roman glass, but various minerals were added to produce coloured glass and also to make the clear colourless glass which became fashionable in the later 1st century AD. Most of the glass at Basinghall is blue-green, but much is colourless and there are a few fragments in dark blue and amber.
Sometimes, sorting these fragments into ever smaller heaps begins to feel endless, and I need a good light. Not a job for these dark evenings - its time to go home …..
Photos: a heap of unsorted Roman glass; Roman glass sorted into the different types of waste
