Emblem of Frost was a currency which was introduced with patch 3.3.0. It was used to purchase ilvl 251 and 264 items. Emblems of Frost were converted into Justice Points with patch 4.0.1 at a rate of 11.58 points per emblem.[1]
The grand total Emblem of Frost available per week is 93:
25x from ICC10
25x from ICC25
5x from ICC10 Weekly Quest
5x from ICC25 Weekly Quest
5x from Weekly Raid Quest
This weekly raid quest is separate to the Icecrown Citadel raid quests that give the [Sack of Frosty Treasures], and both can be completed each week. It also gives 5x Emblem of Triumph.
Tier 10 set pieces, sometimes called the "Emblem" version, are purchasable using [Emblems of Frost] from class vendors.
The normal version of tier 10.5 set pieces, sometimes called the "Sanctified" version or "Tier 10.264", can be bought as an upgrade from the class vendors if you have the tier 10 "Emblem" version. Tier pieces are upgraded by using a token from the 25-man version of Icecrown Citadel, called Mark of Sanctification.
The heroic version of tier 10.5 set pieces, sometimes called the "Heroic Sanctified" version or "Tier 10.277", can be bought as an upgrade from the class vendors if you have the normal tier 10.5 "Sanctified" version. Tier pieces are upgraded by using the heroic version of the token from Icecrown Citadel: Mark of Sanctification (heroic).
Tier 10 armor for each class is currently sold in two locations: in Dalaran, by a vendor for that type (plate, cloth, etc) of armor, and in Icecrown Citadel, by a different vendor for each class.
Emblems of Frost and Emblems of Triumph will be converted to Justice Points at a ratio of 11.58 Justice Points per emblem. Items which were purchased using Emblems of Frost or Emblems of Triumph now require Justice Points instead.