For dualists, mind substance is supposed to be fundamentally different from matter in a number of ways. Two of them:
Mental states can be known directly and with certainty: A person just knows that they are in pain, in love, or that they believe in something specific. Material states don't share this property: we can never know them directly the way we know mental states, we can only infer them indirectly from our senses or from communication with other people.
The identity argument: If mind and matter were the same, then anything that is true about one is true of the other. Since there are things which are true about the mind, but not true about matter, then they cannot be identical.
The key point for your question is that the distinctions between mind and matter apply to any kind of matter (fermions, bosons, quarks, waves, particles, force vectors,...). So mind substance can't be just another family of matter, it has to be something altogether different.
Saul Kripke, David Chalmers, Thomas Nagel are all modern philosophers who argue for this fundamental difference. Frank Jackson was for while did as well, with his famous "Mary the color blind scientist example", but has since changed his mind.
There are many philosophers who argue against dualism, again I will state two. They don't argue so much for mind being another type of matter, instead they argue that dualists are wrong about their being fundamental differences between mind and matter in the first place.
Daniel Dennett argues tries to show that when examined closely, mental states are not as different from physical states as we think they are. For example, he challenges that sensations and beliefs are as certain as we think they are. That we can be just as wrong about our beliefs and sensations as we are about the material world around us. Search for Daniel Dennet "Experienced beer drinker" experiment and his ideas about inverted goggles.
Paul Churchland goes further and claims that mental states don't exist at all. Everything in the world is physical, and the only reason we need mental descriptions is because our science is not advanced enough to describe our brain adequately, in the same way that ancient people used magic and powerful gods to describe physical and astronomical phenomena that now we can explain using purely physical facts.