Betwixt

Betwixt, also translated as Dense, is a material type introduced in Kingdom Hearts II. Betwixt materials contain the essence of In-Between, and are colored grey.

In Kingdom Hearts II, once all Dense materials are obtained, the Moogle will reward Sora with a Serenity Gem.

Design
Betwixt materials are represented by jewels that have an Elemental material structure. They have a dull, opaque grey coloration.

Grey is a color between black and white, which reflects the material's Japanese name, "In-Between". "Dense" can mean "opaque" or "obscure".

Drops

 * Dense Shard: Creeper (8%), Dragoon (12%)
 * Dense Stone: Sniper (12%)
 * Dense Gem: Samurai (12%)
 * Dense Crystal: Berserker (12%)

Drops

 * Betwixt Shard: Sniper (18%), Reaper (18%), Olympus, Twilight Town, Kingdom of Corona
 * Betwixt Stone: Sniper (12%), Reaper (12%), Ninja (18%), Kingdom of Corona, Arendelle, The Caribbean
 * Betwixt Gem: Reaper (8%), Ninja (12%), Arendelle, The Caribbean
 * Betwixt Crystal: Ninja (6%), Berserker (73%), The Caribbean

Kingdom Hearts Melody of Memory

 * Betwixt Shard:   ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,
 * Betwixt Gem:  ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,     ,

Rewards

 * Betwixt Shard: Clear Traverse Town (KH3D) in World Tour (x13), clear The World That Never Was (KH3D) in World Tour (x13).
 * Betwixt Gem: Clear La Cité des Cloches in World Tour (x6), clear Neverland (BBS) in World Tour (x6).

Kingdom Hearts II
Dense materials are used to synthesize the following items:
 * (1 Dense Shard, 1 Dense Stone)
 * (1 Dense Shard, 1 Dense Stone)
 * (9 Dense Shards, 7 Dense Stones, 5 Dense Gems, 3 Dense Crystals)
 * (9 Dense Shards, 7 Dense Stones, 5 Dense Gems, 3 Dense Crystals)
 * (1 Dense Crystal)
 * (3 Dense Shard, 1 Dense Stone)
 * (3 Dense Shard, 1 Dense Stone)
 * (3 Dense Gem, 1 Dense Crystal)
 * (3 Dense Gem, 1 Dense Crystal)

Kingdom Hearts III
Betwixt materials are used to synthesize the following items:
 * (3 Betwixt Shards)
 * (2 Betwixt Gems)
 * (2 Betwixt Gems)
 * (1 Betwixt Crystal)
 * (1 Betwixt Stone)
 * (1 Betwixt Shard)
 * (1 Betwixt Stone)
 * (1 Betwixt Gem)
 * (1 Betwixt Crystal)

Betwixt materials are used to forge the following Keychains:
 * LV4, 5, 7, 8, 10 (3 Betwixt Stones, 3 Betwixt Gems, 1 Betwixt Crystal total)
 * LV4, 5, 7, 8, 10 (3 Betwixt Stones, 3 Betwixt Gems, 1 Betwixt Crystal total)

Kingdom Hearts Melody of Memory
Betwixt materials are used to synthesize the following items:
 * (33 Betwixt Gems)
 * (33 Betwixt Gems)
 * (74 Betwixt Shards)
 * (60 Betwixt Shards)
 * (22 Betwixt Shards)
 * (9 Betwixt Shards)
 * (9 Betwixt Shards)
 * (4 Betwixt Gems)
 * (4 Betwixt Gems)
 * (4 Betwixt Gems)
 * (4 Betwixt Gems)
 * (4 Betwixt Gems)
 * (12 Betwixt Gems)
 * (2 Betwixt Shards)
 * (4 Betwixt Shards)

Notes and references
Mat Duktil