Diorite from Cape Horn Click to enlarge image
One small piece of indigenous rock, a diorite, bears a significance that far outweighs its unpretentious appearance. It was collected from the top of Cape Horn at the southern tip of South America in 1830, and safely deposited in the Australian Museum in 1899. Image: Stuart Humphreys
© Australian Museum

This small piece of diorite, an igneous rock, may appear unpretentious, but it has an incredible history. On 22 May 1826, two ships sailed from Plymouth, England, on a major expedition to chart the southern coast of South America. The first was HMS Adventure, commanded by Captain Phillip Parker King. The second was HMS Beagle, commanded by Captain Robert Fitzroy.

Captain King and the Adventure continued to chart the Chilean coast and Tierra del Fuego while Captain Fitzroy and party from the Beagle stopped to climb Cape Horn. The latter group reached the summit of Cape Horn on 20 April 1830, collecting many pieces of diorite rock. The two ships returned to England with their cargoes of natural history specimens, and Captain King returned to New South Wales a few years later.

Specimen details

  • Origin

    Summit of Cape Horn, Hornos Island, Chile

  • Size

    4 x 4 x 3 cm

  • Date

    Registered 1899, 1910 and 1924

  • Collection number


Summit of Cape Horn Hornos Island Chile 4 x 4 x 3 cm Registered 1899, 1910 and 1924 DR.210 Image: Stuart Humphreys
© Australian Museum

The specimens collected by the ships were destined to remain in English collections. However, one small piece of diorite collected by Captain Fitzroy was presented to Captain King and remained in King’s family as a curio.

Captain King’s son, Philip Gidley King MLC, wrote to the then Director of the Australian Museum, Robert Etheridge Jnr, on 12 December 1899, offering to donate his father’s memento. King’s letter is preserved in the Australian Museum Archives and makes amusing reading as he states: ‘I have a very interesting specimen in my possession which I wish to place somewhere to be kept but not mixed up with other “bits of blue metal”’. Etheridge called on King the following Tuesday afternoon, 19 December, to accept the specimen, which may be the only geological specimen from this expedition in Australia.

The Cape Horn specimen brings to life an age of adventure and hazardous sea voyages, the result of a long chain of events which eventually brought it into our collection.

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