Surviving bills for jewellery supplied to Anna of Denmark mostly date from 1605 to 1615, totalling around £40,000. Her servants Margaret Hartsyde and Dorothea Silking often dealt with him on her behalf. She often wore a miniature portrait of Isabella Clara Eugenia and Heriot mended its locket case twice. Surviving pieces made by Heriot for Anne include a gold miniature case set with her initials in diamonds, now held by the Fitzwilliam Museum, which the queen may have gifted to her lady-in-waiting Anne Livingstone, and a pair of earrings which include the enamelled face of an African man, in a private collection. The earrings were itemised by Heriot in 1609 as "two pendants made as more's heads and all sett with diamonds price £70." They may reflect her fascination with the representation of African people in the theatre, as in her "Masque of Blackness".