To make metal in Little Alchemy, you mainly need to combine fire with stone or lava. Here are the working methods:

Main ways to make metal

  1. Stone + Fire = Metal
  1. Lava + Air = Metal

How to get the ingredients

  • Earth + Fire = Lava
  • Earth + Earth = Soil → Soil + Fire = Stone

So a simple full path from basic elements is:

  1. Earth + Earth → Soil
  2. Soil + Fire → Stone
  3. Stone + Fire → Metal

Or, using the lava path:

  1. Earth + Fire → Lava
  2. Lava + Air → Metal

Extra: what to do with metal

Once you have metal, you can start unlocking lots of cool elements, for example:

  • Metal + Water → Rust
  • Metal + Human → Weapon or Tool (varies by version)
  • Metal + Fire → Steel

Quick HTML table of core combos

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Goal Combination
Stone Earth + Earth = Soil → Soil + Fire = Stone
Lava Earth + Fire = Lava
Metal (method 1) Stone + Fire = Metal
Metal (method 2) Lava + Air = Metal
Steel Metal + Fire = Steel (in some versions/vid guides)

TL;DR: Make stone (Earth + Earth → Soil, Soil + Fire → Stone), then mix Stone + Fire for metal, or use Lava + Air as an alternative route.

Information gathered from public forums or data available on the internet and portrayed here.