Defense gems are yellow gems, orange gems, green gems, and meta gems.

Northrend Gems

Color	Name	Effect(s)
Meta	[Eternal Earthsiege Diamond]	+21 Defense Rating	5% Shield Block Value
Yellow	[Thick Dragon's Eye]	+34 Defense Rating
	[Thick King's Amber]	+20 Defense Rating
	[Thick Autumn's Glow]	+16 Defense Rating
	[Perfect Thick Sun Crystal]	+14 Defense Rating
	[Thick Sun Crystal]	+12 Defense Rating
Orange	[Champion's Ametrine]	+10 Defense Rating	+10 Strength
	[Glimmering Ametrine]	+10 Defense Rating	+10 Parry Rating
	[Resolute Ametrine]	+10 Defense Rating	+10 Expertise Rating
	[Stalwart Ametrine]	+10 Defense Rating	+10 Dodge Rating
	[Champion's Monarch Topaz]	+8 Defense Rating	+8 Strength
	[Glimmering Monarch Topaz]	+8 Defense Rating	+8 Parry Rating
	[Resolute Monarch Topaz]	+8 Defense Rating	+8 Expertise Rating
	[Stalwart Monarch Topaz]	+8 Defense Rating	+8 Dodge Rating
	[Perfect Champion's Huge Citrine]	+7 Defense Rating	+7 Strength
	[Perfect Glimmering Huge Citrine]	+7 Defense Rating	+7 Parry Rating
	[Perfect Resolute Huge Citrine]	+7 Defense Rating	+7 Expertise Rating
	[Perfect Stalwart Huge Citrine]	+7 Defense Rating	+7 Dodge Rating
	[Champion's Huge Citrine]	+6 Defense Rating	+6 Strength
	[Glimmering Huge Citrine]	+6 Defense Rating	+6 Parry Rating
	[Resolute Huge Citrine]	+6 Defense Rating	+6 Expertise Rating
	[Stalwart Huge Citrine]	+6 Defense Rating	+6 Dodge Rating
Green	[Enduring Eye of Zul]	+10 Defense Rating	+15 Stamina
	[Enduring Forest Emerald]	+8 Defense Rating	+12 Stamina
	[Perfect Enduring Dark Jade]	+7 Defense Rating	+11 Stamina
	[Enduring Dark Jade]	+6 Defense Rating	+9 Stamina

Outland Gems

Color	Name	Effect(s)
Meta	[Tenacious Earthstorm Diamond]	+12 Defense Rating	Chance to Restore Health on hit
	[Eternal Earthstorm Diamond]	+12 Defense Rating	+5% Shield Block Value
Yellow	[Facet of Eternity]	+12 Defense Rating
	[Thick Lionseye]	+10 Defense Rating
	[Thick Dawnstone]	+8 Defense Rating
	[Thick Golden Draenite]	+6 Defense Rating
	[Thick Amber]	+4 Defense Rating
Orange	[Champion's Fire Opal]	+4 Defense Rating	+5 Strength
	[Glimmering Fire Opal]	+4 Defense Rating	+5 Parry Rating
	[Glistening Fire Opal]	+5 Defense Rating	+4 Agility
	[Stalwart Fire Opal]	+5 Defense Rating	+4 Dodge Rating
Green	[Effulgent Chrysoprase]	+5 Defense Rating	2 Mana every 5 sec
	[Enduring Seaspray Emerald]	+5 Defense Rating	+7 Stamina
	[Enduring Chrysoprase]	+5 Defense Rating	+6 Stamina
	[Enduring Talasite]	+4 Defense Rating	+6 Stamina
	[Enduring Deep Peridot]	+3 Defense Rating	+4 Stamina

Patch changes

• Patch 3.2.0 (04-Aug-2009):
  • [Dragon's Eye] gems stat bonuses increased.
  • We will be removing the prismatic quality of the jewelcrafter-only [Dragon's Eye] gems. 
    

v • d • e Socket gems By material Red [Blood Garnet] · [Living Ruby] · [Crimson Spinel] [Bloodstone] · [Scarlet Ruby] · [Cardinal Ruby] [Carnelian] · [Inferno Ruby] · [Queen's Garnet]† [Tiger Opal] · [Primordial Ruby] Orange [Flame Spessarite] · [Noble Topaz] · [Pyrestone] [Huge Citrine] · [Monarch Topaz] · [Ametrine] [Hessonite] · [Ember Topaz] · [Lava Coral]† [Pandarian Garnet] · [Vermilion Onyx] Yellow [Golden Draenite] · [Dawnstone] · [Lionseye] [Sun Crystal] · [Autumn's Glow] · [King's Amber] [Alicite] · [Amberjewel] · [Lightstone]† [Sunstone] · [Sun's Radiance] Green [Deep Peridot] · [Talasite] · [Seaspray Emerald] [Dark Jade] · [Forest Emerald] · [Eye of Zul] [Jasper] · [Dream Emerald] · [Elven Peridot]† [Alexandrite] · [Wild Jade] Blue [Azure Moonstone] · [Star of Elune] · [Empyrean Sapphire] [Chalcedony] · [Sky Sapphire] · [Majestic Zircon] [Zephyrite] · [Ocean Sapphire] · [Deepholm Iolite]† [Lapis Lazuli] · [River's Heart] Purple [Jaggal Pearl] · [Shadow Pearl] · [Shadow Draenite] · [Nightseye] · [Shadowsong Amethyst] [Shadow Crystal] · [Twilight Opal] · [Dreadstone] [Nightstone] · [Demonseye] · [Shadow Spinel]† [Roguestone] · [Imperial Amethyst] Prismatic [Northsea Pearl] · [Dragon's Eye] · [Siren's Tear] [Chimera's Eye] [Serpent's Eye] Meta [Earthstorm Diamond] · [Skyfire Diamond] · [Starfire Diamond] · [Unstable Diamond] [Earthsiege Diamond] · [Earthshatter Diamond] · [Skyflare Diamond] · [Starflare Diamond] [Shadowspirit Diamond] [Primal Diamond] Cogwheel [Flashing] · [Fractured] · [Precise] · [Quick] · [Rigid] · [Smooth] · [Sparkling] · [Subtle] By category By stats Agility · Intellect · Spirit · Stamina · Strength · Attack Power · Critical strike · Hit rating · Haste rating · Resilience · Spell Power · Spell Penetration · Mana every 5 Seconds · Threat reduction · Defense · Dodge · Parry By source Vendors · Factions · PvP · Quests · Enchanting By quality/stats Uncommon · Perfect uncommon · Rare · Epic Uncommon · Perfect uncommon · Rare · Epic † Added in Patch 4.3.