The Copper Island crown grants cover the area about 1.5 kilometres west from and including Clifton Point on the west coast of Tzartus Island, Barclay Sound. Most of mineralization occurs on the Mountain claim, 800 metres from Clifton Point.

Work recorded from 1899 to 1901 comprises prospecting, stripping, trenching, opencuts, a 4 metre shaft, and a 31 metre tunnel. Much of the ore, approximately 1814 tonnes, was mined from the main showing and stockpiled. In 1961, 690 metres of diamond drilling were completed.

Tzartus Island is underlain by volcanic rocks of the Lower Jurassic Bonanza Group and limestones of the Upper Triassic Quatsino Formation, Vancouver Group. These are intruded by the granitic rocks of the Early to Middle Jurassic Island Plutonic Suite. East and northwest trending Tertiary faults transect the island.

The orebodies are hosted in gently (25 to 30 degrees) east dipping interbedded andesitic tuffs and tuffaceous sediments. These are in fault-contact (northwest trending) with diorite.

The main showing (largely mined out) is an irregular shaped body of massive magnetite. This is roughly 12 by 21 metres and is close to the contact. Massive mineralization grades into irregular lenses of magnetite (up to 10 centimetres thick) interlayered with garnet or a quartz-epidote skarn. Garnet and minor chalcopyrite and pyrite impregnate the magnetite lenses. Other showings, exposed at higher elevations to the east, are in contact with diorite and comprise similar magnetite-garnet and magnetite-quartz-epidote layering conformable to primary bedding. This grades into garnetite then unaltered tuff. Mineralization is cut by numerous diorite and granodiorite sills and dykes. Total surface exposure is estimated at 272 metres between elevations of 200 and 245 metres with shallow depth (cut off by diorite intrusions).

The most representative sample, taken from the stockpile in 1902, assayed 50.4 per cent iron, 0.053 per cent phosphorus and 0.3 per cent sulphur (Minister of Mines Annual Report 1902, page 218). The ore is not considered to be of commercial grade.