Doll Name Jem/Jerrica (1st edition/Made in Spain)
Stock #  630005
Hasbro package contents listing Contiene: Muñeca Jem/Jerrica 30 cms. Micrófono, vestido de escena, mallas, zapatos brillantes, alfiler de cabello, pulsera, cinturón reversible, vestido de día, sombrero, zapatos de salón, gafas oscuras, peana para lafigura. 
  • This isn't a regular identification page but a listing of the differences between my Spanish & US-issued 1st Edition Jem/Jerrica
  • By Spanish, I literally mean she was made in Spain, not to be confused with the Mexican-made Jem dolls, which also have Spanish text on the boxes.

doll: The Made in Spain Jem doll closely resembles the regular US-issue China & Hong Kong made 1st Edition Jem/Jerrica dolls. Her head is very much like a Made in China star-capped Jem head, with the exception of not having star-caps, otherwise the markings and make up scheme are the same. 
The earrings also stuck out a little more than a regular US-issued doll, not sure if that's peculiar to my doll or not. Otherwise her head looks a lot like a China-made doll and has the same markings.
The skintone of the Spanish-made Jem/Jerrica has a distinctly beige tone to it - it's not very noticeable unless right next to a Made in China or Hong Kong doll. Mine can not sit without her pelvis making a "popping" noise (similar to bending the knees). Overall it seemed as though the pelvis was just in wrong somehow- she even has a slightly pot-bellied appearance. I'm not sure if this is typical of Spanish dolls or if I just got a particularly bad one. 
The easiest way to tell if you have a Spanish doll is to simply look at her markings on her back! Notice she has the smaller battery cover.
The most obvious difference in her body is the feet- you will notice they are arched more than the average Jem doll's (far left is the Spanish foot)

Microphone differences - various 1st edition Jem/Jerricas and Flash N' Sizzle Jem at the end.
belt - the brocade is rotated 90 degrees (like the Mexican belt) but otherwise looks comparable to a Hong Kong or China made doll's belt.
Dress - the Spanish one (on the left) looks very much like a Made in China dress - slightly bigger, paler and smoother material, compared to the Hong Kong dress on the right. Like the China dresses, it closes on the right.

shoes; If I found the Spanish ones loose, I wouldn't be able to differentiate them from a regular pair of 1st Edition Jem/Jerrica thick-sided shoes. These Jem ones aren't rubbery like the Jerrica shoes are.

hair picks; Neither Spain or Mexico have the iridescent sheen. The Spanish one has the TM by the logo, Mexican does not. The Mexican is kind of pearly, Spanish isn't - it kinda reminds me of a bar of soap in terms of colour ;)

sunglasses: The regular (China/Hong Kong) 1st Edition Jem/Jerrica ones can vary, and be more like the Spanish ones in shape and colour too. The Mexican ones, yet again, are the oddballs here, being much paler and of a different shape entirely (look at the nose rest area to see what I mean). 

stand: my Spanish Jem came with the same stand as my Italian 1st issue Aja doll, it has the TM mark.
zapatos de salón; ^_^ Whatever this translate to, it's Jerrica's funny rubbery shoes. This is the main difference that I know of between Spanish and US/Hong Kong dolls, they are pretty neat!

Items not listed in Hasbro's box contents (not all dolls came with the same posters and inserts, this is a listing of what I got personally with my dolls)
cassette tape
In Spain, Jem/Jerrica came with a tape too. I'm not sure if they all did or not, mine is twist-tied right into the backer, it's not an in-store promotion. 
Other than licensing information, says nothing but the Jem logo and Cara A/Cara B. The songs are in English (mostly), the dialogue is in Spanish. 
Side A:
A man reciting the Jem story in Spanish, interspersed with some Jem and Misfits songs (shown below), some have clapping and/or introductions during them. 
Jem Story
Outta My Way
Only the Beginning
Winning is Everything
Jem Theme (short, in Spanish! Different from the Mexican one)
Side B:
Jem Theme (long version)
Like A Dream
Twilight in Paris
Gettin' Down to Business
I got My Eye On You
Too Close

Box, liner and inserts not previously noted in Hasbro's box contents above.
*not all fashions came with the same posters and inserts, this is a listing of what I got personally with the doll listed on this page.
Box: First year Jem/Jerrica box with side flap, Spanish version. There are Jemstar points on the box. It is unique in that the top flap tucks into the top of the box, it's not glued down.
Side panel reads: © 1986 MB España/S.A. under Berne &/Universal Copyright/Convention/Made in Valencia, Spain
Box liner - hot pink, not dark pink like Canada and US issued dolls. (see more on Box Liners)
poster - 1 sided First year illustrated poster, with "Verdaderamente Fantàstica" written in place of "Truly Outrageous". (See more on posters)
Jem hair styling instructions, text is Spanish, printed in Valencia. It is the version without the stand instructions.