虫の甲殻 [mushi no koukaku] or 'insect's carapace' in Japanese.
Final Fantasy XII
Buy: - (sell: 680 gil)
Use: Platinum Helm & Platinum Armor & Platinum Shield
Drop: Antares, Killer Mantis, Preying Mantis, Scythe Mantis
Steal: Scythe Mantis
Poach Antares, Killer Mantis, Preying Mantis, Scythe Mantis
Description: A thick insect carapace, hard as gemsteel. Only those from the largest insects have any value, and the price varies with the piece's luster.
Revenant Wings
Buy: 300 gil (sell: 150 gil)
Shop: Material Shop, chapter 4 onwards
Use: Ice Brand, Mythril Lance, Mythril Staff, Rod of Ice, Trident
Obtain: Maleficent Mayhem (harvest 67%), Gucuma Qul Sky Pirate Melee (harvest 67%), Fane of Tehp Qul Summoning Melee (harvest 67%)
Description: Hard and glossy insect shell. Price varies by size and color
Other: low-grade Timeworn Carapace
Grimoire of the Rift

Buy: - (sell: 50 gil)
Use: Rondel, Silver Sword, Xankbras
Reward: Our Playground x2 (once), A Harvest Hand (repeatable)
Type: Bone, Rank: —
Description: An insect shell so hard, it seems to be almost metal. The price of these shells differs depending on pattern and coloration.
Final Fantasy Tactics S

Buy: - (sell: ? gil)
Use: Rapier, Shield Ring
Obtain: Western Orda Woodsea/Hot Sand Road
Description: ?
Category: Item