Not to be confused with shards, (a type of currency from BATTD) or the possibility of converting BATTD items into shards (i.e. All items but Legendary rarity or Martian Trader exclusive items can be sharded).
Shardable is a status effect introduced in Bloons TD 5 characterized by the capability of a bloon spawning shards if the current layer is popped while frozen. It is exclusive to Ice Shards and its higher upgrades.
Shardable is represented on the Bloons Wiki with 
, which depicts the upgrade portrait for Ice Shards in Bloons TD 6, since its upgrade icon is already used for Shatter 
and is a core example of something that combines Sharp 
and Frozen-Popping Power 
. Shardable is a status effect because it is a temporary condition that causes the affected bloon to spawn shards if the bloon's current layer was popped while frozen. Shardable is often accompanied from a Freeze 
status effect.
Bloons affected by Shardable will be able to spawn a spray of shards while the bloon was frozen. Any attack that destroys the layer of bloon while penetrating (not removing) the frozen layer will spawn the shards. If the frozen layer naturally defrosts, the Shardable status effect will wear off. If the frozen layer is removed without damage (e.g. Druid of the Storm), then the shardable effect will not spawn (?).
Ice Shards and above are the only examples that can apply Shardable status effect.
