I found this fossil 36 yrs ago on a beach near Sannox, Island of Arran, UK. It is approximately 15 mm wide at the widest cross section of the tubular structure(s) and the length of the large central structure is about 60 mm. The colours in the photograph are reasonably accurate. the structure is segmented into approx. 30 x 2 mm segments along its length. The white areas on the tubular structures look like quartz, extremely thin film, shiny, reflective. The quartz 'domains' are quite aligned with the segments and are broken by the segment boundaries. There is a very obvious red line running down the middle of the large structure. The rock is very hard and has thin bands through it in planes running parallel to the large structure - like a layer cake. There are many bands and you can see 2 or 3 smaller tubular structures squashed in the layers - ends sticking out.
I showed this to some colleagues in the Palaeontology department and a couple of them who work on fossil echinoderms thought that it looks like a section of crinoid stem and that the red staining looks like Haematite. They thought it was possibly Carboniferous in age but can't be sure of that.