"Can't find any history on the place....."
You know what might be really useful ? Some sort of global electronic network that allows you to use a free indexing service to - almost instantly - search for information by doing nothing more complicated than entering search terms such as "Bixhead" ?
http://www.pastscape.org.uk/hob.asp That's the English Heritage description of the quarries.
And
http://www.gsia.org.uk/reprints/1987/gi198717.pdf
Which is a .pdf of a document that looks like it was written by a local history buff in 1987.
To be fair, there's not that much info (but then I only spent two minutes looking !) Short version : They're post medieval, though there has been quarrying in the area since at least the 15th Century. Eastnor Castle is probably built of stone from here.