How many syllables in 'diamond'

[Aparecium]

I'm in SE England and always say it in two syllables: DI-mond. But I've just been listening to an audiobook read in a very RP accent, and every character gives it three syllables: DI-a-mond. The a is more of a neutral shwah sound than a flat a.

AFAIK I speak RP with a slight foreign accent at times (1st gen immigrant).

So, which is right?

@Joboomer , sounds not spelling IMO.
Many words can be both n-syllable and n+1-syllable, depending on accent.
e.g medicine [ˈmɛd(ɪ)s(ɪ)n], vegetable [ˈvɛdʒ(ɪ)təbl]

I’m in Lancashire (which does have various accent). All have two syllables-

Dymubd
Lybri
Wenzdi

(Tried to spell them as phonetically as possible)

Dymund!