Spica is a high-ranked gun that requires the Guns 4 License in order to equip (Guns 5 in the Zodiac versions). It provides 34 attack and 5% critical, and can be bought for 13,000 gil at Balfonheim Port.
In the Zodiac versions, it now provides 38 Attack, 10 Evade, 50 CT, 5% critical rate and requires the Guns 5 license for 90 LP. It can be bought in Balfonheim Port for 11,000 gil, found as a treasure in Feywood (The Edge of Reason), poached from Shadonir (5% chance), or from the bazaar for 8,900 gil after selling Ichthon Scale x4, Silver Liquid x5, and Wind Crystal x7. It can be equipped by the Machinist and Shikari.