If you had been paying attention all along, she has probably mentioned SOMEthing she would like to have. Ex: when I was dating the hubby, I mentioned a boombox might be nice to take bowling with my team. 6 months later at Xmas, there it was. He remembered all that time. (Not that I had *really* been serious, BUT it was the fact that he remembered something in passing)
Odds are from the articles we have read that your 'moon rock' is as fake as silicone breasts. The US gov has NOT allowed one iota of that out. lol The hubby follows the collectible scene in weird areas like that.
Stick with what she likes and stay safe!