I have only three of the gems, thus I cannot complete the challenges to receive a reward; where can I find the other 7 resonance gems?

There are only 5. Where have you found the ones you have?

There are? Ten, I am further than I originally thought!

I found two on the man inside the ruin itself, and another from the merchant with the Silt Strider. Do you know where the last two are?

I got one from the miscellaneous items trader in Raven Rock... I didn't know what it was for.
I should check the invy of the guy with the silt strider. I think I've looked but he didn't have one. Maybe I just needed to wait or something.

They may show up randomly in loot or shopkeep inventories.

Now that you say that, I think I actually got it off of her... The memories were just combining from my fatigue (too much Dragonborn!!!!).

One in fahlba... Something or other. It's a dwemer ruin with these really big gears. Also there is one in that place you clear with neloth. In the room where neloth waits for you while you go ahead, there is a locked do that can only be reached after neloth has given you the cube back.

Hmm... I thought I cleared out those places... Can you remember where in the dwemer ruin with the gears the resonator is?

Near the middle of the map a little west.

i dont even know where to find them. I found two on the dead guy but clueless about the others.

Thanks! I'll be on it when I can next play!