Shiny, malleable and light, tin is truly a fascinating metal. Luckily for us, its low melting point also means that tin is one of the easiest metals to extract from its ore. By using some of the same methods utilised by Bronze Age smelters, a modest amount of labour can extract small globules of relatively pure tin from ore-containing rock. Once separated, these small tin "prills" can be easily remelted and moulded into any shape that you might desire.
Obtain several large pieces of cassiterite-rich rock. This rock contains tin in the form of SnO2. It has a dull brown colour, and can be bought online or at a mineral show.
Crush the ore into dime-sized pieces with your hammer. Place the pieces and any residual dust into the mortar and pestle and grind the rock until it reaches the consistency of coarse sand.
Remove the ground rock into a pan carefully, and gently run a fine stream of water over the gravel. Swirl the mixture several times, allowing the cassiterite to gather at the bottom of the pan. Remove any remaining rock and dry the brown cassiterite particles in the sun for several hours.
Break the hardwood charcoal into pieces 2cm in diameter, and place a layer 3cm high at the bottom of your crucible. Ignite the charcoal using a small amount of lighter fluid, and use the blowpipe to blow a gentle stream of air over the entire layer until it glows red hot.
Layer the powdered ore on top of the charcoal and place more charcoal on the pile until the crucible is filled. Resume blowing air into the layers, with the tip of the blowpipe placed into the charcoal. Add more charcoal as needed.
Stop blowing after 15 minutes, and allow the crucible to cool. Remove the charcoal, and you should see small globules of ash-covered tin at the bottom of the container.
Pick ore that has a slight sparkle. This usually indicates high concentrations of cassiterite.
Be careful to let the tin cool before touching it. It can remain hot long after the charcoal seems safe to remove.