Cook 2023 Black Swan Obsidian Silver Coin PCGS 69. Silver / 99.9% / 2oz (62.2g). This is the economic term “Black Swan”. The Black Swan effect refers to financial crises that have a very low probability of occurring but create massive impact when they do happen, such as the 911 terrorist attacks in 2001 and the 2008 subprime mortgage crisis. ABOUT US & FURTHER INFO. THIS IS PROFESSIONAL KOREA NUMISMATIC SHOP. SEARCHING FOR THOSE WHO TRADES OR WANT TO COLLECT KOREA CURRENCIES. WE WILL PROVIDE THE BEST CURRENCY SERVICE. PLEASE CONFIRM YOUR ADDRESS IS CORRECT. IT TAKES MORE 2 OR 3 WEEKS TO RECEIVE ITEMS IN SOUTH AMERICA, RUSSIAN FEDERATION. OTHERWISE, WE CAN’T GUARANTEE YOUR ITEM IS STILL AVAILABLE. OTHER TERMS & CONDITIONS. PLEASE DO NOT FORGET TO LEAVE US FIVE STARS ON.