SOLVED. Middle Grade/ Children's Fantasy series. 6 tween girls create a portal to a magical world where they each get to learn a different type of magic (earth, water, fire, etc.). Cover: green. Read around 2008-2013.

[Maya]

It's a middle-grade/children's fantasy book (1st in a series but I only read the first one) about 6 tween girls who discover a portal to another world. They're all best friends and have a sort of club meeting in a shed, and they realize that they've each received a mysterious charm. When they put them all together it sticks to the table and forms a portal. They all go through to that world where there are 6 different tribes/cultures of some fantasy species (water, earth, fire, etc). Each girl gets to learn a different type of magic from the different tribes. All the characters had stock personalities, like the sporty one, the artsy one, etc. and there was a section at the end of the book that had basically a summary of each girl and a drawing of her. One of the girls really loved rainbow-colored things. Also, I don't think it was very popular, since I remember the only reason I got it was that it showed up in the mail as a free sample, as promotion for the rest of the series I think. The year range I read it was around 2008 - 2013.

[Maya]

Found it! Wellspring of Magic by Jan Fields

[Rainbowheart]

Glad you found it!

Wellspring of Magic for the link.