Cannonite – Occurrence, Properties, and Distribution

Oct 21 2014

Chemical Formula - Bi₂O(SO₄)(OH)₂

Cannonite was named after Benjamin Bartlett Cannon, V, an amateur mineralogist from Seattle, Washington, USA, who discovered the first specimens.

Properties of Cannonite

The following are the key properties of cannonite:

Cell Data
- Space group: P2₁/c
- a = 7.700(3)
- b = 13.839(6)
- c = 5.686(2)
- β = 109.11(3)°
- Z = 4
Crystal Data
- Monoclinic
- Point group: 2m
- As equant to prismatic crystals, elongated along [102], to 200 µm
- Granular massive
- X-ray powder pattern: 3.206 (100), 1.984 (90), 2.924 (70), 3.644 (60), 3.466 (60), 2.782 (50), 3.513 (40)

Chemical Composition

Elements	Content 1	Content 2
Bi₂O₃	82.53	82.61
SO₃	14.18	14.20
H₂O	[3.29]	3.19
Total	[100.00]	100.00

Optical Properties
- Optical Class: Biaxial
- α = [1.91]
- β = n.d.
- γ = [1.99]
- 2V(meas.) = n.d.

Estimated Properties

Electron density	Bulk density (electron density) = 5.57 g/cm³ note: Specific gravity of cannonite = 6.54 g/cm³
Photoelectric	PE_Cannonite = 1,401.72 barns/electron U=PE_Cannonite x ρ electron density = 7,801.39 barns/cm³
Fermion index	Fermion index = 0.0005229667 Boson index = 0.9994770333
Radioactivity	Cannonite is not radioactive

How to Identify Cannonite

Cannonite can be identified in the field by its colorless structure. Its transparent form has no cleavage. This mineral has a adamantine luster with white streak. The fracture on this mineral is brittle – conchoidal. The density of cannonite is 6.515 g/cm³ with a hardness of 4 – approximate to fluorite.

Global Distribution

Cannonite is distributed in the following places:

USA - From the Tunnel Extension mine, Marysvale, Ohio district, PiuteCo., Utah
Canada – Québec, Abitibi-Témiscamingue, Abitibi RCM, La Motte Moly Hill mine
Italy – Lombardy, Brescia Province, Camonica Valley, Pisogne, Fraine Duadello Mine; Piedmont, Verbano-Cusio-Ossola Province, Ossola Valley Crodo, Alfenza Mine
Japan - Kanto region, Tochigi Prefecture, Ashio, Ashio mine.

Occurrence of Cannonite and Useful Mineral Association

Cannonite typically occurs in an alteration product in a Cu–Bi–Au-sulfide deposit. It is often associated with minerals such as covellite, quartz, cuprobismutite, and bismuthinite.