An unusual simile for rust, though of course, once seen, it seems natural. A beech hedge in winter has an intense and often uniform rust colour.
‘… and the corners were stacked with old weapons that were as rich with rust as a hedge of winter beech.’
See also a quotation from Zorba the Greek in which it is the rusty old weapons themselves that are the metaphor.
Source: Mervyn Peake, Titus Groan, introduction by Anthony Burgess (London: Vintage Books, 1998), p. 152
Photo credit: Gellinger at pixabay.com