Full Idea
The ring on my finger is supposed to have a real essence, whereby it is gold, from whence those qualities flow which I find in it, viz. its colour, weight, hardness, fusibility, fixedness, and change of colour upon a slight touch of mercury, etc.
Gist of Idea
Gold is supposed to have a real essence, from whence its detectable properties flow
Source
John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.31.06)
Book Reference
Locke,John: 'Essay Concerning Human Understanding', ed/tr. Nidditch,P.H. [OUP 1979], p.379
A Reaction
This is Locke's notion of essence, as simply the underlying cause of the detectable properties. Oderberg says real essences are not hidden, but are the macro-features we all know gold to have. Locke never denies real essences.