A method is provided for heavy metal stabilisation comprising: mixing waste, comprising heavy metals, with molecular sieve with the proviso that carbon-based molecular sieve is excluded, and clay; and vitrifying the mixture. In particular, a method comprising the steps of: preparing a pre-stabilised mixture by mixing waste, comprising heavy metals, with the molecular sieve, and optionally other chemicals; mixing the pre-stabilised mixture with clay; and vitrifying the obtained mixture is provided. It also provides a product comprising heavy metals that have been stabilised into the structure of the clay-based ceramic matrix, wherein the product is a vitrified product of a mixture of at least waste, comprising heavy metals, molecular sieve (with the proviso that carbon-based molecular sieve is excluded) and clay.