Since Elizabeth was famously a virgin, it is no surprise she owned several unicorn horns. I am intrigued that this one has also been used for medicinal purposes. This is from Thomas Platter’s Travels in England 1599. Platter’s visit to Nonesuch Palace included a tour of the rooms, including
They showed us the circular horn of a unicorn, 7 of my spans in length, had been filed down to heal the sick, resembled ivory, although the black veins where it had been turned were still visible. It was hollow inside so that a nerve could run through it.