2018 Alien Invasion 2 oz Pure Silver Coin with Ruby Swarovsky Crystals. ALIEN INVASION – 2018 10,000 CFA Francs 2 oz Pure Silver Coin with Ruby Red Swarovski Crystals- Republic of Chad. A coin commemorating Aliens and UFO. 2 oz Pure Silver Rimless Coin. Ruby Red Swarovski Crystals. Features:Antique Finish, Ruby-Red Swarovski Crystal Mintage: 500 pcs Material: Pure Silver (99.99%) Finish: Antique Issuer: Republic of Chad Weight: 2 oz Diameter: 50 mm Face Value: 10,000 CFA Francs. Credit / debit card.