{
    "feature": "miningmaster:ore_gem_random",
    "placement": [
        {
            "type": "minecraft:count",
            "count": 3
        },
        {
            "type": "minecraft:in_square"
        },
        {
            "type": "minecraft:height_range",
            "height": {
                "type": "minecraft:trapezoid",
                "min_inclusive": {
                   "absolute": -50
                },
                "max_inclusive": {
                   "absolute": 60
                }
            }
        },
        {
            "type": "minecraft:biome"
        }
    ]
}