Passage: Earl Thomas granted the manor to his steward, Robert de Holland, in February 1308. In 1311, Robert obtained a licence to crenellate from Edward II in order to fortify the manor house, and the more modest earlier building was converted into a castle between 1311 and 1322. Local tradition says that the stone was obtained from a quarry on the site of what is now Melbourne Pool. The records show £1,313 was spent on the project in the year 1313–14, of which £548 was paid to masons for dressing stone. Several masons working on the project were involved in an affray at Ravenstone in 1315. The important medieval buildings in Melbourne were constructed from the local bedrock, Millstone Grit. This is a coarsely grained sandstone which can be worked to produce good-quality ashlar. The village was centred around the church, castle and High Street until the late 18th century.Earl Thomas, with other barons, captured King Edward's favourite, Piers Gaveston, and killed him in 1312. Nevertheless, the King stayed at Melbourne in 1314. For a time, after Edward's defeat at Bannockburn, the earl, a friend of the Scots, controlled most of England, but by 1321 Edward had raised an army and driven Thomas from the Midlands. The Lancastrian castles at Melbourne and Tutbury were left deserted and looted by the local populace. Earl Thomas was finally defeated at the Battle of Boroughbridge in 1322. He was swiftly executed, and Robert de Holland was beheaded in 1328. The King sent a garrison to Melbourne and appointed a steward, Ralph Basset, to replace the incumbent, John de Hardedeshull. In March, those who had stolen from the castle were arrested, and by April Edward had withdrawn his troops. He appointed Robert Tocher and Roger de Beler in 1323 to help administer his possessions in Melbourne using money obtained from confiscations of rebel property in Staffordshire. Edward stayed at Melbourne again in 1325, and while there he issued a right to collect tolls to the men of nearby Swarkestone to repair the bridge over the Trent.

Question: What materials were the structures in Melbourne made of?
the local bedrock, Millstone Grit