The gameboard is a 7x9 grid. The players draw from a bag containing seventy-eight tiles called nuggets. Each nugget represents one of six metals. Each player, in turn, places one, two or three nuggets on the gameboard. The nuggets placed must match each other, however. After placement of the nuggets, the player may purchase up to two shares of stock of the mines represented by the nuggets on the gameboard. The player then ends the turn by replacing the nuggets played with nuggets from the bag. Every subsequent turn has each player beginning the turn by collecting profit based on the number of shares owned and the size of each mine and rarity of the metal therein.The game ends when the gameboard is filled. All players cash out the value of their stocks and the player with the most money is declared the victor. - BoardGameGeek