Yup, she can't get anywhere on that with the tools available.

She tries scratching the stone with her pliers, too.

Nope!

Excellent! Just for completeness, when her parents are in bed she'll take it down to the unfinished basement and whack it with a hammer, trying to break the stone. (Any warrantee she offers is not going to cover hammer-smashing, but she wants to know anyway.)

Her hammer bounces off and the ring goes flying into a pile of basement junk!

Whoops! Time to go fish it out. Maybe it's under the spare garden hose.

Yeah, there it is, totally unharmed.

Wow. She continues to love this magic system.

(Sadly, she is too ignorant of popular culture to make the obvious Lord of the Rings reference, so the narration is just going to have to allude to it.)

Does it still turn her invisible properly, after all that?

Yup!

Great! Except now there's nothing to distract her from the fact that she still has to figure out how much to charge. She goes back to the critter corners of the internet, and looks at all the enchanted object prices she can find.

Luck charms go for anywhere from seventy-five to seven thousand dollars. Vintage stuff and less popular oddball items are more expensive.

Hmm. Maybe eight hundred per, with durability and a warranty costing an extra two hundred? She can raise or drop prices later, if she can't get buyers or gets so many buyers she and Brenda can't keep up. She brings the (banged-up, scratched, amateurishly rewired, but doubly magical) ring and a few copies each of the invisibility and durability spells to Dungeons and Dragons. Onward, to get that box back to its rightful owner and maybe find out what's in it!

They get the box back to its owner! It turns out to contain a copy of the text of a prophecy which sure sounds like it could be what the cultists are reacting to!

Well, the description of the people who are supposedly destined to bring peace to two feuding cities could be said to match their party, but only if you interpret that one bit in a rather implausible way. It's probably not about them. What were they even doing before this whole mess started?

Escaping the desert. That's handled now. Joseph's character is spooked about the prophecy and attempts to suggest that the party hare off to his home country to do some things mentioned in his backstory.

On the one hand, bringing peace to two feuding cities is hardly the worst way they could be spending their time. On the other hand, if the prophecy is about them, it'll come true regardless, so why not hare off to Joseph's character's home country? Margaret is fine with whatever everyone else wants to do.

Xavier isn't dropping any hints one way or another, so off they go to Joseph's character's country to let him pay the orphanage that raised him a bunch of his share of loot.

Margaret's paladin approves of this sort of thing, and chips in some of her own loot too. Also if any of the orphans are down a few HP, she can heal now. Of course, they have to get there first.

Wandering monster! And end session.

And thank Xavier for another fun session and follow Brenda outside. "I have durability figured out, now."

"That's... really fast, I'd been assuming it took months to do anything."

"It gets easier with practice." 

"It does?"

"Yeah, spell design is a lot like a math puzzle."

"I don't find math puzzles that much easier after practicing them. Maybe you don't mean Sudoku?"