Gem
Gems return in Diablo III, and they're set to be a much larger part of the game. The item type works just as it did in Diablo 2; Gems are still small objects that have no function on their own, which add various bonuses when placed in item sockets. The bonuses they grant have changed though, and there are many more quality levels of gems (14 in D3, vs. 5 in D2).
They can still be upgraded in a 3<1 ratio, though that process requires the Jeweler, rather than the Horadric Cube, and it's widely suspected that gems will be used in more than items, with a use in the Talisman perhaps making them even more valuable.
- Information about Gems in Diablo II.
Diablo III Gems
Gems in Diablo 3 have evolved during the game's development. Early on, they were similar to World of Warcraft gems, with a "cut" listed in their properties. For instance, a "chipped star topaz" was seen in an early gameplay movie.
This feature was removed over time, and as of late 2010 gems are much closer to how they were in Diablo 2; no "cut" is listed, and they simply have quality levels; 14 of them (compared to 5 in Diablo 2).
Gems grant bonuses when socketed into items of all types, and they might have other functions, such as in the Talisman.
Gem Types
A complete list of gems is not yet available. Most of the types found in Diablo 2 have been seen so far in Diablo 3, including Rubies, Sapphires, Emeralds, Topazes, and Amethysts. Diamonds have not been seen, but are expected. It's not known if Skulls will return, or if there are any other precious stone types of gems yet to be revealed.
Upgrading Gems
Gems upgrade in D3 just as the did in D2. Three of one level will combine into one of the next level.[1] This is accomplished by taking the gems to the Jeweler, rather than simply doing it yourself with a Horadric Cube, but the function is the same.
One improvement over Diablo 2 is that gems of like type/level will stack up to 10 high in a single inventory space. Players will thus not sacrifice so much space for gem storage.
Gems can be found at levels 1-5, and with a maximum level of 14, the process of upgrading a gem all the way to the top should be a very long term project. If the current 3>1 upgrading ratio remains unchanged, then it would require 1,594,323 level 1 gems to make a single level 14 gem (3^(14 - 1)). To give you an idea how long this would take, just upgrading the gems that many times would take 664 hours of nonstop clicking, assuming you could complete one upgrade per second.
The math isn't quite as daunting if you assume you'll be upgrading level 5 gems; it only requires 19,683 level 5 gems to make one level 14 gem. Happily, Jay Wilson has said that they're open to tweaking the formulae if it's taking too long; instead of 3>1 they might turn it down to 2>1 at higher levels, as was done with higher level Runes in Diablo II. It would only require 512 L1 gems to upgrade to a L14, if the requirement was 2>1 all the way up.
Unsocketing Gem
One key fact to consider is that in Diablo III, gems (and other socketables) can be removed from sockets, by the Jeweler, without losing the gem. This was not the case in Diablo II, where runes, gems, and jewels were in an item forever, or were destroyed by the unsocket recipe. This fundamentally alters the upgrading project, since instead of gems sitting useless in your stash until they are all the way to the top level (as they did in Diablo 2), characters in Diablo III will be using their highest level gems all the time, and gaining considerable benefits from the gem.
If a character's goal is to gain a huge bonus from a L14 gem in their shield, they'll be using that type of gem at L9, L10, L11, and so on, as they slowly upgrade it towards L14. This should make the upgrading process seem a little less lengthy, especially as it will take weeks or months for each additional level of improvement with a high level gem.
Gem Bonuses
Little is yet known of the bonuses gems will provide. It's assumed by most fans that the higher level gems will grant very high bonuses, and that the bonus won't simply increase at say, +3 per level. That doesn't seem like enough of an improvement to make the months and months of collecting and upgrading required to create a L14 gem worth it.
As for what the gems will provide bonuses to, that's also unknown. The only recently confirmed stat is from a normal (level 3) Emerald, as seen in the Gamescom 2010 Artisan video. That gem granted:
- Weapon: +4% Casting Speed.
- Helms: Attackers take 7 damage.
- Other: +7 dexterity
In Diablo 2, v1.13, a level 3 emerald grants:
- Weapons: +40 poison damage over 5 seconds
- Armor & Helms: +5 dexterity.
- Shields: +22% Poison Resistance
The numerical bonuses (but not the type of bonus) from gems have changed over the course of Diablo 2's patches, but clearly there are major differences in more than the numbers. Diablo 3 grants entirely different types of bonuses, and categorizes the socketable items differently as well.
These changes are largely due to the game's different combat mechanics and character requirements, but were also somewhat required by the different itemization issues. For instance, Sapphires in helms/armor grant +mana in Diablo 2, but +mana isn't a viable bonus in Diablo 3, since only the Witch Doctor has mana for a resource.
