This is one of those subjects that gets people tied into rather pointless arguments. One approach is the simple one that involves no knowledge whatever of etymology, and that is - choose “s” (typically British form) and be done with it. For reasons of editorial simplicity and the avoidance of egregious error, the “s” form of such words is the Editor’s House Rule in Geoscientist. Let me explain…
Some verbs in “-ise/ -ize” are NEVER properly spelt with a “z”, on either side of the Atlantic, because they are borrowed from French. They include: advertise, advise, apprise, arise, chastise, circumcise, comprise, compromise, despise, disenfranchise, disguise, exercise, merchandise, prise (in the sense of opening), supervise, surmise – and so forth. “Organise”, however, is usually spelt with a “z” in the US.
In the UK we therefore enjoy the benefit of being able to choose “s” all the time. and know that we are not wrong to do so: whereas ize sometimes will be wrong.
Greek roots of such words not borrowed from French are generally the same and end in “-izein”. But there are complications, because “Baptize” (as it was spelt in the 13th Century in English, and is the oldest English word in –ize/-ise known to etymologists) comes from the Latin - Baptizare (spelt with a z) despite the fact that the French have now (like us) chosen to use an “s” in Baptiser. So which is right? Well, -ise has become right.
The rule therefore is that (except in the US where a “z” is compulsory for certain non-French-derived words in –ize) you may use s or z without fear, according to taste. Use an “s” and you will never be “wrong”.
For this reason there is no definitive answer to your question. “Mineralisation” can be spelt correctly with either form. It is a matter of taste, preference and custom. Feel free to choose. But once you choose, be consistent!