Monistic non-dualists hold that only one thing is real.
Dualists hold that two things are real, and ne'er the twain shall meet.
Pluralists (myself included) hold that many things are real, and many categories of things are real, and that leakage or transference can and does occur between and among categories.
One style of non-duality is the style espoused by many materialists and reductionists: those for whom only matter---physical stuff you can hold in your hand---exists and is real.
Another style of non-duality is the style espoused by many philosophers, metaphysicians, phenomenalists and some religious believers. For monists of the idealist school, mind is the only thing that exists and is real.
Another style of non-duality is that espoused by those for whom only deity / consciousness exists and is real: many schools of Hindu and Buddhist thought, transcendentalists, pantheists and panentheists.
In my view, pluralists are closer to the truth by sheer simple virtue of being open to more possibilities. Henotheists, for example, accept a single god while accepting the existence or possible existence of other gods.
Myself? I believe there is not just one or two domains, but an infinity of domains and sub-domains.
Within the domain of mind, for example, there are sub-domains such as thought, memory and dreams.
Alongside the domain of "normal" matter are the domains of "abnormal" matter such as dark matter, and "virtual" matter (comprising particles that wink in and out of existence in fantastically short spaces of time).
Alongside the domain of physical things is the domain of non-physical things that exist whether or not there is a mind to conceive them: mathematical formulae, recipes, unimplemented designs, unbuilt structures, numbers, laws of nature, algorithms, axioms and many more.
There's the domain of instinct and the domain of intuition. I can't figure out whether the domain of emotions is a sub-domain of mind or a fully fledged domain in its own right.
There are also those domains that cut across dimensions with which we are unfamiliar or incapable of entering or conceiving. Various schools of string theory have different ideas about how many dimensions there are to reality---four, ten, eleven, twenty six, and thirty one are some of the numbers bandied about. What they have in common is the idea that we don't perceive these extra dimensions because they are rolled up (compactified) very, very, very small. Not at all like little jewels, though---I just introduced the word "jewel" to give me a trick ending to this post about non-jewelism.
Perhaps no jewels, but all possibilities...
Blessings Friend.
COMMENTS? Come on... gimme your best shot!