'gemstone-adorned' is a compound of the noun 'gemstone' and the past-participle adjective 'adorned'. 'Gemstone' is built from 'gem' + 'stone'; 'gem' originates from Old French 'gemme' (from Latin 'gemma') meaning 'precious stone' and 'stone' comes from Old English 'stān'. 'Adorned' comes from Latin 'adornare' (ad- 'to' + ornare 'to equip, furnish, ornament'), via Old French 'adorner' into Middle English.

The elements evolved separately: Latin 'gemma' → Old French 'gemme' → English 'gem', Old English 'stān' → 'stone'; Latin 'adornare' → Old French 'adorner' → Middle English 'adorn' → past participle 'adorned'. In Modern English these elements combine productively into compound adjectives like 'gemstone-adorned'.

The components originally referred specifically to a 'precious stone' and the action 'to ornament'; together they have retained the straightforward combined meaning 'decorated with gemstones' in modern usage.