The fire damaged buildings and equipment at the quarry.
A investigation has been launched into the cause of a fire at a north quarry.
The blaze at Achscrabster quarry is understood to have caused extensive damage to a temporary building and heavy plant equipment, including diggers and a tanker.
Two crews of firefighters from Thurso spent several hours at the scene after being alerted to the emergency at around 8.20am yesterday.
They used two sets of breathing apparatus, one hose reel jet and two jets to bring the fire under control. Water was sprayed onto four hot acetylene gas cylinders to cool them and prevent explosions.
Thermal imaging cameras were also used.
It is understood that no one was hurt.
Police set up a wide cordon around the quarry following the incident.
A fire services spokesman said: “A joint investigation by Police Scotland and Scottish Fire and Rescue Service has been launched.”
