The Diablo 2 Wiki
The Diablo 2 Wiki archive is available for anyone looking for information on Diablo 2. All information here is pre-D2R but contains a lot of useful information that is still relevant. Updated sections for new D2R features can be found on the PureDiablo Diablo 2 section

Sapphire

From Diablo 2 Wiki

Sapphires are very usefully socketed in weapons for the slowing/chilling bonus they provide, especially for low level characters.


Diablo III Sapphires

Sapphires are not found in Diablo III. Only Rubies, Topazes, Emeralds, and Amethysts are found in D3C, though other gem types might return in expansions. See the Diablo III wiki for more details.


Diablo II: Lord of Destruction

The following bonuses are granted by Sapphires in D2X.

QualityWeaponHelm or ArmorShieldClvl Req
ChippedSapphire-chipped.gif+1-3 Cold Damage
1 second Cold Time
+10 to Maximum Mana+12% to Cold Resistance1
FlawedSapphire-flawed.gif+3-5 Cold Damage
1.4 second Cold Time
+17 to Maximum Mana+16% to Cold Resistance5
NormalSapphire-normal.gif+4-7 Cold Damage
2 second Cold Time
+24 to Maximum Mana+22% to Cold Resistance12
FlawlessSapphire-flawless.gif+6-10 Cold Damage
2.4 second Cold Time
+31 to Maximum Mana+28% to Cold Resistance15
PerfectSapphire-perfect.gif+10-14 Cold Damage
3 second Cold Time
+38 to Maximum Mana+40% to Cold Resistance18


D2C Sapphire Stats

Sapphires have slightly different stats in D2C.


Sapphire

QualityWeaponHelm or ArmorShieldSell PriceClvl Req
ChippedSapphire-chipped.gif+1-2 cold damage
1 second cold time
+7 to maximum mana+11% cold resistance1251
FlawedSapphire-flawed.gif+1-2 cold damage
1.4 second cold time
+10 to maximum mana+15% to cold resistance3755
NormalSapphire-normal.gif+2-3 cold damage
2 second cold time
+14 to maximum mana+19% to cold resistance125012
FlawlessSapphire-flawless.gif+3-4 cold damage
2.4 second cold time
+19 to maximum mana+24% to cold resistance375015
PerfectSapphire-perfect.gif+3-6 cold damage
3 second cold time
+24 to maximum mana+29% to cold resistance750018