Bit of an update - just got sample back and it had zero (i.e. not even a trace) of asbestos in my sample - it was, however, confirmed as being vermiculite.
Can officially stop the cacky pants, now.
Hope this helps any future readers - if it looks like vermiculite, get it tested!
I have just read about the Carriage Works online - horrific reading.
I just wonder what I am doing now, on a daily basis, that will be the new asbestos of the future (routers, microwaves, mobile phones, PC monitors).
Anyway, time to cheer up now.
Thanks everyone for your input. Much appreciated and, thank god, literally no harm done.