The spelling of /g/ is <g> or <gg>, but we also see <gh> in ghee and <gu> in rogue . The /z/ sound is spelled <z>, <zz>, <se> or <s> as a 3rd-person inflection.
This is a contrast between a stop and a fricative, both voiced but well separated in the mouth. It does not cause any problems.
The only taboo word pairs are bugger buzzer and buggered/buzzard.
Interesting pairs include:
corgis causes
goggling gosling
haggard hazard
The figure for the mean density is 0.5%. The set makes 38 semantic contrasts, a loading of 68%.
berg burrs big biz boogie boozy boogies boozes bug buzz bugged buzzed bugging buzzing bugger buzzer buggers buzzers buggered buzzard buggies buzzes corgis causes Doug does dug does eagerly easily eagle easel eagles easels erg errs fig fizz fug fuzz fuggy fuzzy fuggier fuzzier fuggiest fuzziest fugue fuse Gambia Zambia Gambian Zambian Gambians Zambians gap zap gaps zaps ghee zee goggling gosling goo zoo guessed zest hag has haggard hazard jag jazz jagged jazzed jagging jazzing jaggy jazzy jaggier jazzier jaggiest jazziest league leas leg Les morgue maws muggy muzzy muggier muzzier muggiest muzziest plague plays roguery rosary rogueries rosaries rogue rose shindig shindies swig swiz whig whizz wig whizz wigged whizzed wigging whizzing
John Higgins, Shaftesbury, October 2010.