gems

[cavetroll]

is there a book for D&D that has a better variety of gems and jewels and thier properties for creating magic items

[Zacchaeus]

Hi cavetroll welcome to FG. I have to assume you mean 5e. The only gems in any published WotC material are found in the DMG as treasure items. There's a section there about creating magic items and some spells require specific gems to work, but there's not a special source book.

[LordEntrails]

For creating magic items? No, I don't remember coming across anything like that when I did a bit of similar research.

There are also 2 other FG modules for gems for 5E that pre-date the DMG. One is on the DMsGuild.com from Agmar, and the other in linked in my signature. I don't remember the details of Agmar's version. Mine just has the "typical" fantasy gems in a variety of sizes with corresponding values.