These are the best you can get. Alan Parsons' Verdict 'Lovely sound but would probably be preferred by the classical listeners rather than people who like to Rock 'n Roll. At 3,000 a pair these are the top end of the domestic market. The 'Sculpture Series' is only a cottage industry - producing about 24 pairs of speakers a year, with no major outlet apart from Inigo Jones. They are the best slates in the world.
Slate has a natural roughness unless it is rubbed down to produce a really smooth surface.
It is resistant to harsh weather, pollution and acts as a natural insulator, staying cool in summer and warm in winter. It is used for cladding, flooring, roofing, furniture, worktops, clockfaces, ashtrays, chess boards, fruit bowls etc. It varies in colour from blue grey to blue black, heather red, etc. The colour and composition vary depending on the mineral content of the original rock - and these all depend on what type of rock was being eroded on land at the time. The haematite coats the grains of the mud, masking the green colour of the chlorite.