Wasn't hematite quarried in an opencast at Friden near Newhaven where the brick works were/are? Your query has triggered off memories of when I first studied geology (1951) I was told of this deposit, it was a bit of a dump. The ironstone mines tend to be on the edge of the coal deposits on the east of of the County (Derbyshire) - lots have been written about them in PDMHS Bulletins. There was a brick works up near Brassington (at Harboro Rocks) which we were once shewn over - very interesting where silica bricks were made (material came by boat from India to Liverpool, then railway to Harboro via the old High Peak Railway).
Very interestingly there were the ochre deposits found when mining at Brassington. William Dewsbury the partner at Derby Crown China bought the orchre from James Dawson who was mining agent (possibly deputy Barmaster at Brassington Liberty) from a mine at Brassington for his glazes (this was in the late 1700's or thereabouts). James Dawson was also involved with the Hubberdale mines and agent for the Duke of Devonshire at his mines in Yorkshire. James Dawson was a bit of a shady character and was the son of Adam Dawson (of Elton) the Overseer at the Oxclose mine in the 1770's and who also went to Black Hole mine to oversee it when the mine went bankrupt - Nellie Kirkham wrote about this in one of her articles (I am writing this information from memory so please excuse if slightly incorrect). Benjamin Dawson his brother became Overseer at Oxclose after his father Adam, he also owned shares in the Oxclose sough.
Sorry if this is not of help. Trust you are well, many apologies for not being in contact recently.