Maybe for the dwarves, the quartz mineral specifically associates romantic interests.
Maybe the quartz structure corresponds to anatomy? Something like?
• female transparent crystalline (crystal, amethyst, etcetera)
• intersex translucent chalcedony
• male opaque jasper
Maybe its cut corresponds to gender?
• feminine rounded, round, oval, multifacet brilliant, simple cabochon
• queergender partly rounded and partly angular, marquis, pear, heart
• masculine angular, square, rectangular, emerald
Maybe the location of the jewelry corresponds to community?
• woman head adornment, crown, earings
• nonbinary torso adornment, necklace, broach, belt
• man arm adornment, ring, armlet, bracer
May its metal inset signifies interest?
• silver representing self identity (other metals represent ones interests)
• gold both romantic and sexual
• platinum sexual (aro)
• mithril romantic (ace)
• adamantine friendship, neither romantic nor sexual (aroace)