Jane was living in Bath when she and Cassandra received Topaz Crosses from their younger brother Charles.
In a letter Jane wrote to Cassandra dated 26-27 May 1801, Jane tells her sister that she had been ‘to the very top of Kingsdown and had a very pleasant drive, -one pleasure succeeds another rapidly’.
Upon her return home to Sydney Terrace, two letters were waiting for her on the hall table. One was from their youngest brother Charles who was serving with the Navy. He wrote about his reward for capturing an enemy privateer.
The other letter was from Cassandra, and Jane added the news of his gift into her reply,
He had received £30 for his share of the privateer and expects £10 more -but of what avail is it to take prizes if he lays out the produce in presents to his Sisters. He has been buying Gold chains and Topaze Crosses for us; -he must be well scolded.
Although Charles talked about buying gold chains with the crosses, he sent the crosses without chains as you see them below. Jane owned the cross on the left.

Jane was so touched by the gift from Charles that she wrote it into her novel Mansfield Park ten years later.
Fanny’s brother William was a naval midshipman, and he gives Fanny “a very pretty amber cross” which he “had brought her from Sicily”.
Where are they now?
You can see both Topaz Crosses when you visit the Jane Austen’s House Museum at Chawton. They are permanently on display with Jane’s ring and bracelet.
Want your own Topaz Cross?
Do you want to wear your own Jane Austen Topaz Cross? I bought mine from the Jane Austen Centre Bath.

Reference:
Jane Austen’s House Museum
Jane Austen Centre Bath Shop