Now some of the items that helped two of them, Charlotte and Emily, to translate the bleak windswept heather and wild moors landscape into the dramatic settings for Wuthering Heights and Jane Eyre are up for sale in what could be the last such auction for years.

Charlotte's desk and Emily's geometry set and art box could fetch as much as £17,000 when they go under the hammer at Sotheby's in London next month.

The Brontë treasures – which will be auctioned on December 17 – belonged to William Law, an avid 19th century collector of Brontëana who made frequent visits to Haworth where he bought items from Charlotte Brontë's widower, the Rev Arthur Bell Nicholls.

So keen was Law to make sure the items were not mistaken for worthless artefacts he went to the trouble of installing metal plaques, engraving the words "Desk belonging to Charlotte Brontë. Displayed in memory of W.Law Esq" on the George III mahogany desk, valued at up to £10,000, and "Artists box of Emily Jane Brontë, Ladies' Literary Society,Manchester" on the Regency mahogany artist's box, valued with the geometry set at up to £7,000.

One of the first sales from Law's collection was a paint box owned by Emily, which sold in 1907 at Sotheby's.

As the auction house deputy director, Dr Phillip Errington, explained these are the final few pieces of that collection.

He added: "You have to go back a long way back to find items like this for sale.

"The opportunity to buy something the Brontës owned is not common at all.

"We had a sale a few years ago, in December 2004, that included a unknown painting of Charlotte Brontë, a box and a pistol which was unmistakenly from Wuthering Heights."

Emily was only 30 when she died in 1848, having lived a very sheltered life in Haworth, West Yorkshire amid the bleak moors where she penned Wuthering Heights.

Her paint box and geometry set would have been one of the few items of entertainment she owned.

The front compartment contains three quill nibs, the middle compartment contains a square glass bottle and includes space for two round ink or water bottles, while the back section contains a paint tray with remnants of paint. Below the tray is space for the geometry set and a compartment containing three miniature envelopes, two sticks of sealing wax and a small circular box of miniature gummed labels.

The geometry set is in a morocco-covered box featuring a metallic label, which is inscribed : EJB.

The box contains seven items including a folding bone ruler and a retractable steel nib pen, and its front drawer includes nine ceramic fitted mixing dishes which are mostly stamped.

These stamps are for Ackermann, 96 The Strand, London and thanks to this address Sotheby's says the box can be dated back as far as 1827.

Ann Dinsdale, Collections Manager for the Brontë Parsonage Museum, explained: "They are very important pieces, especially anything relating to Emily Brontë.

"Because she was never famous during her own lifetime very few of her personal items or manuscripts were kept and are extremely rare."

Dr Errington agreed: "We have two very special items here. Items of Emily Brontë's are the holy grail of Brontë collections because she died a lot younger than her sister."

Charlotte, who also died young at the age of 37 in 1855 while pregnant, was also a keen artist.

Dr Errington said he was very excited about her desk because of its rarity. He said: "I wouldn't like to say definitively that this was Charlotte Brontë's writing desk she wrote her books on, but it was obviously important."