Smoky quartz looks great with turquoise and swarovski pacific opal.
Or brown lip shell ( like abalone, but brown.) Lillypilly makes beautiful laser etched pendants ( www.fusionbeads.com )
Or try mixing vintaj natural brass with aqua glass and crystal beads for a vintage inspired look. Design ideas www.vintaj.com and to purchase their products www.fusionbeads.com or www.galenabeads.com. Galena Beads also sells seedbead mixes (great alone or used as spacers) there is one called Coffee and Chocolate Lover's mix.
Hope this helps