Generate Ore?

How do I generate Ore and other minerals like Minecraft but for a 2D game not a 3D game? I want minerals to generate in clumps realistically. The problem is that I have no idea where to even begin to do this. I was thinking well I’ll just pick a random point in my world then place some ore their. Then get the neighboring blocks and put ore their but it doesn’t look natural at all.

So please help how should I go about doing this?

Look up fractal generation or perlin noise calculations.