A striking Cristillium (aluminium based) metal plant pot saucer by Conrah Products, England. Circa 1970s vintage. 
This modernist anodised shallow dish, with engraved diamond pattern, was made in England by Conrah, pat. no 8855/67. The name 'Cristillium' is also used to describe these decorative metalwares from the 1960s-1970s. The range was designed by Ronald Hughes I believe. The vases and candle holders were often cylindrical, as is this example. Cast from aluminium, they were anodised to give the colour, then cut through by machine to reveal a shiny silvery aluminium pattern beneath.
This piece is an unusual shape and is a matte mid sky blue with shiny and reflective diamond geometric patterns. It catches the light in a striking reflective way. Striking yet simple Modernist British design. Simple round low cylinder shaped, we have a 17.5cm wide holder, 5cm tall. The inner flat area is 10cm wide. It has the original green felt base pads, and the central stamp which reads: "A Conrah Product. Prov Pat. 855/67. Made in England".
Externally and in use it's very good. It does have marks inside, one deep.  
Free P&P to the UK.