In the end of the movie when they are holding the Jewish ritual to open the ark, Belloq is dressed in special robes - those described in Exodus 28 and 39 as the garb of the priests of the Tabernacle. Included in the ensemble was a breastplate with 12 gemstones, each said to represent a tribe of Israel. Well, I got geeky and tried to see if Belloq's breastplate stones matched those described, but it didn't seem to correspond! I was disappointed.
Exodus describes the stones as the following:
sardius, topaz, emerald
turquoise, sapphire, diamond
jacinth, agate, amethyst
beryl, onyx, jasper
In the movie, at least the stones in place of the sardius, sapphire and jacinth seem wrong. Sardius is red and not greenish-looking and I don't think sapphire are red or jacinth green (they are usually orange...). I mean, sometimes stones can be all different colors, depending on the chemical irregularities and impurities, but...Hmmm.
I checked the stones of New Jerusalem (Revelation chapter 21) but these are different from both.
Well, I dunno. No internet sites help me find out who chose to make the costumes as they did for the movie. gakkari... At least it was fun^^
[Edit: Monday 7.51pm]
Wikipedia's article enhanced my confusion, but is very interesting, none-the-less!!