Lot's of ores are just byproducts of the processing of other ores. Like He production is mostly a consequence of natural gas extraction. If you don't extract the high volume profitable (and often environmentally messy) common ore, you don't get any significant amount of the "rare earths".

   Selenium and Cobalt come from Copper mining
   Indium Germanium and Gallium come from Zinc mining
   Nb Nd Pr Sd come from Iron mining
   Yt Nd etc come from Bauxite and Phosphate mining

An interesting thing can happen (and has with Indium) where the demand for the "byproduct" exceeds the relative demand for the main ore (Zinc) causing the price to rise dramatically (for ITO conductors in LCD displays).

There are other places you can get these metals, but they aren't economically viable. Building an infrastructure for cleanly and reliably processing them in volume is clearly important though.

▲ rors 5 days ago | parent | next [-]

A bit of a tangent but the same byproduct effect is seen in the production of sherry casks for finishing Scotch.

A lot of sherry bodegas only really exist to churn out barrels for whisky distillers.

	▲	hinkley 5 days ago \| parent \| next [-]
		I love port and sherry finished scotch but I do feel like it’s cheating the idea of single malt.
	▲	te_chris 5 days ago \| parent \| prev [-]
		Glad they do, those who ignore sherry and their brandies are missing out.

▲ grues-dinner 5 days ago | parent | prev [-]

I feel like with a jankier sprite-pack and a sprinkling of Java Swing UI, Factorio could market itself as a multi-thousand/seat/year supply chain education platform.