Crystal chooses not to bond?

Hi,
I have had this small citrine for 7 years. And after a sleepover, I found out a week later (today) that my citrine has gone missing. Sleepover at my house, I just moved my pillow (citrine was in it) to a different room and moved back after guest left. I found the amethyst (same place with citrine) on the floor but I couldn't find the citrine at all after turning the room upside down.

Has that ever happened to anyone? Is it a sign that the crystal doesn't want me anymore? I loved that piece!

No

From what I have read and know it means it gave you all it had to give or you simply do not need it anymore.

I once lost some rose quartz around the time I met my baby's father. I then found it again a few weeks after we broke up. Perhaps the crystals do have a mind of their own and know when and where to find us.

No, it has to be somewhere. It's a solid object, it can't just *poofff* into the ether. I don't hold with the notion that crystals disappear when "they don't want us anymore", etc. When things fall to the ground, you'd be surprised at how far they can ricochet, particularly if they are sharp-edged. Your citrine is in your home somewhere, assuming of course that it hasn't been mistaken (by anyone else) as random junk-on-the-floor to be picked up and thrown away.