Is mineral up in Orkney essentially close to miracle fuel? (8)

'fuel?' is the definition.
(kerosine is a kind of fuel)

'is mineral up in orkney essentially close to miracle' is the wordplay.
'mineral' becomes 'ore' (ore is a kind of mineral).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'in' is an insertion indicator.
'essentially' indicates the central letters.
'close to' suggests the final letters (the close of something is the end).
The centre of 'orkney' is 'kn'.
The last letter of 'miracle' is 'e'.
'is'+'ore'='isore'
'isore' in reverse letter order is 'erosi'.
'erosi' put inside 'kn' is 'kerosin'.
'kerosin'+'e'='KEROSINE'