These are supposed to be really hard wearing - at least I hope so. I've made them from Romney wool. There are quite a few dyes in them - cochineal, onion skins, brazilwood, Sticta coronata, Eucalyptus nicholi. I've made the heels detachable (see below) so they can be reknitted should they wear out in the distant future.
When I first tried knitting socks all I could find in a 3-ply was baby wool. This is most unsuitable for socks and goes into holes in no time. Fortunately I found a pattern for socks with Aladdin heels in an old Patons Woolcraft book. So that's the design I used and I've been reknitting them ever since. In case you're not familiar with the idea, the heel is kept detachable by grafting with a contrasting thread when returning to knit the main sock. When the heel wears through, you remove the thread - here a white thread - detach the heel, unpick it or cut it off, knit it again (I am doubling the thickness as I do this) and graft it back to the sock. It looks like new and there are no bulky darns. You can do this with most sock patterns.
Unpicked and ready to reknit
A different sock reknitted and grafted. It just needs the sides to be sewed up.
The first sock finished.