I think you're thinking of precious stones and precious metals.
I had a date show up once with Hershey Kisses and a packet of Marigold Seeds... it was our first date and he said, he wanted our relationship to grow....
&, it was our last date too.
But, I thought it was original ...
Reminds me of the old joke about the little girl asking her mother:
"Mommy, how do babies get made?"
Mother - "Well, honey, a Daddy puts his seed into a mommy's tummy and that seed grows into a baby."
The little girl thinks about this for a minute and then asks - "Mommy, how does the seed get into your tummy, do you have to swallow it?"
And the mother says, "No, honey, that's not how you get babies, that's how you get jewelry!"