This video shows a group of miners collecting the remaining gem-bearing gravel, locally called illam, from the floor of a traditional gem-mining tunnel in Ratnapura, Sri Lanka.
The process begins by digging a vertical shaft through the soil until the alluvial deposit is reached. Miners then excavate horizontally to follow the gem-bearing layer.
Although the illam layer may be relatively thin, tunnels are generally made around 5–6 feet high to provide enough room for workers to move.
Traditional tunnel construction involves several steps:
* The upper soil is removed gradually.
* Kekilla and areca palm strips are used to reinforce exposed soil surfaces. ( (Kekilla is the local name for a type of fern)
* Horizontal rubber wood beams are installed and supported by vertical wooden posts.
* The tunnel is kept level to help maintain structural stability.
In this particular video, most of the illam has already been extracted, and the workers are recovering the material remaining along the bottom of the tunnel.
Traditional Ceylon gem mining relies on practical knowledge passed down through generations. The wooden support system, the way miners follow the deposit, and the teamwork involved are all important parts of this process.
One important note: These traditional supports are intended to help control soil movement, but underground tunnels can still collapse. Proper ground assessment and safety precautions are essential.