Rosewater Oasis I dream in oily fluorescent swirls

He wouldn't be brushed off so easily. 

"There has to be some heirarchy, even among stones," he said, glancing up at her with one eyebrow quirked. "After all; would fifty of the same type of gem be the same as five of ten different gems?" He asked. He tilted his head from side to side, as though weighing the options. "Variety, Widower- those we trade with may have a preference, and we'd be better off having a multitude of things to bargain with, and they won't all be seen as equal....Especially if we choose to market them differently."

He was an aspiring businessman, after all. And though she might have desired silence, they had important matters to discuss, and he valued her opinion enough to put her through the agony of sorting out the details. 

"Now how we decide the value, that's something to figure out. The overall condition and size of the stone are pretty obvious factors, but type of stone, rarity of stone, and of course popularity and demand, those ought to influence each stone's price." With every emphasis, he turned the stones over, causing the water's surface to ripple. He reminded himself to be gentle; it wasn't easy to do when he was getting enthusiastic about the idea of talking value. 

"You have the best eye for these things. I'll want to count on you to determine a stone's value." He said.