All the pieces seen here were made with a technique known as lost-wax casting. First, the artist makes a wax model of the item they wish to create, then envelops the model in clay. When the clay is fired, the wax melts and drains out, leaving a hollow space inside what is now a ceramic mold. Next, molten metal is poured into the mold, occupying the space left behind by the wax. Once hardened, the mold is broken apart to reveal the finished metal item. 
 

Making metalworks this way requires a lot of experience and skill, and some of the earrings seen here display flaws. Other pieces in this room demonstrate the level to which artists—especially those of the Tairona and Quimbaya traditions—perfected this technique, producing elaborate three-dimensional poporos (containers for lime powder) and figurative pendants.