sexagonus

sexagonus [cf. CL sex, ἑξάγωνος], six-sided, hexagonal (in quot. of stone or crystal, prob. w. ref. to cross-section). ibi [sc. in Hibernia] ‥ gignitur lapis ~us [Brompton 1073: saxagonis; Trevisa: þat stoon saxagonus], scilicet iris, qui soli appositus format in aere celestem arcum Higd. I 32 (= Fordun Chr. I 18, Bower I 19).