SOLVED. Sci-Fi YA a girl gets transported to a alien planet with the boy she liked. An opal stone part of their transportation? [s]

[Shannan]

When I was in the sixth grade (1996) Our school library had a book I borrowed 2 or 3 times. What I can remember is a girl gets transported to a alien planet with the boy she liked. I feel like their was something about an Opel stone being part of the transportation. This is all I'm grabbing on to.

[Tab]

Shannan, do you remember anything about the cover?
Was it part of a series?

Do you remember anything about the aliens/planet? Were they humanoid, friendly, scary, green, etc?

[Shannan]

I think the cover had grey clouds and a black Opal in the middle of it. I don't think there were any aliens in it. Someone was chasing them into the alien word from ours.

[Cupcakedoll]

The cover matches, and what I remember of the plot it mostly matches.

[Shannan]

Oh my gosh, this might it! Thanks!

[Lobstergirl, au gratin]

Come back and let us know.

[Lobstergirl, au gratin]

Shannan, was that your book?

[Lobstergirl, au gratin]

No response and Shannan left the group. But she shelved and rated the book on March 10, 2016 so I'm moving this to Solved.