Here are the gems and enchants that are relevant to tanking. This is from my limited prot pally point of view. I don’t know what gems or enchants the other tanks need but I’m sure that most are the same.

Enchants

Head

1. Arcanum of the Stalwart Protector revered with Argent Crusade

Shoulders

1. Greater Inscription of the Pinnacle exalted with Son’s of Hodir

Legs

1. Frosthide Leg Armor 55 stam, 22 agi; LW, easy mats if none are in ah

Feet

1. Tuskarr’s Vitality 15 stam, minor run speed increase; The loss of 7 stam is very minor but the run speed increase may come in handy on some fights
2. Enchant Boots – Greater Fortitude 22 stam; 3 lesser cosmic essence, 3 infinite dust

Weapon

1. Enchant Weapon – Potency 20 strength, increase shield block value by 10 (via modifiers), BC enchant; this is my personal choice
2. Titanium Weapon Chain 28 hit rating, reduces the length of disarm effects by 50%

Shield

1. Enchant Shield – Defense 20 def, 6 Infinite Dust and 6 Eternal Earth
2. Titanium Plating 40 shield block value, from blacksmiths

Waist

1. Eternal Belt Buckle buy in AH, put a blue gem 24 stam gem in

Wrist

1. Enchant Bracer – Major Stamina 40 stam; 4 greater cosmic essence, 1 abyss crystal

Hands

1. Enchant Gloves – Armsman 2% increased threat, 10 parry;  my personal choice
2. Enchant Gloves – Expertise 20 expertise, 20 infinite dust, 2 greater cosmic essence

Chest

1. Enchant Chest – Greater Defense 22 defense to chest, 10 infinite dust, 1 eternal earth
2. Enchant Chest – Powerful Stats 10 to all stats, expensive mats (15 infinite dust, 4 abyss crystals)
3. Enchant Chest – Super Stats 8 to all stats, relatively inexpensive (4 infinite dust, 2 lesser cosmic essence)

Back

1. Enchant Cloak – Titanweave 16 def, 2 titanium bars, 2 dream shards, 8 infinite dust

Gems

Blue (green, purple)

1. Solid Sky Sapphire 24 stam

Red (orange, purple)

1. Champion’s Monarch Topaz 8 def, 8 str
2. Sovereign Twilight Opal 8 str, 12 stam

Yellow (orange, green)

1. Thick Autumn’s Glow 16 def
2. Enduring Forest Emerald 8 def, 12 stam

Prismatic

1. Solid Dragon’s Eye JC only, +41 stam
2. Enchanted Tear 6 all stats; unique equipped

Meta

1. Austere Earthsiege Diamond 32 stam, 2% inc armor value; my personal choice
2. Eternal Earthsiege Diamond 21 def, 5% shield block value