Such a heart-warming manga.
I finished it yesterday after a few hours of reading. I thought that I would just try a chapter or two, but at the end I read all 35 chapters. That says it all. :)
The story takes place in the United States, 1991. All the character are American, except of one Japanese guy, who is a minor character. In addition, the manga is a spin-off of the manga "Cipher', but it is not necessary to read "Cipher" first. I haven't read "Cipher", and I enjoyed and understood the plot of "Alexandrite" very much. I would give 8 to the story.
The art was beautiful in my opinion. I have read many manga series (I think I have XD), and I have noticed that sometimes manga series from the nineties suffer from horrible art, that later improves (... and sometimes does not). That wasn't the case in "Alexandrite". 8. :)
The character development was great! I could really see a change in their characters, and for such a short manga (35-chapter long) that's quite a suprise. This fact gives 9 for the characters.
For enjoyment I would give this manga a nice 10, and overall 9. I recommend this manga for shoujo lovers, even though I think that people who shoujo is not their cup of tea could enjoy it- That's the magic in this manga.