The Mineral hafnon
Hafnon is isomorphous with the mineral Zircon. It is almost identical to Zircon in physical properties, and occurs together with it. Thought to be Zircon, it is rarely identified separately when found. Because of this, Hafnon is hardly known to mineral collectors, and in reality it is much more prevalent than perceived. The name Hafnon is derived from a combination of the words hafnium and Zircon.
Gray, brown, brownish-red, orange, black
Hafnium silicate, often with some zirconium and occasionally with some uranium, thorium, and yttrium. It can contain up to 45 percent of zirconium in its structure; if it exceeds that then it is no longer Hafnon but Zircon.
Crystal shape and weight
In rare earth
granite pegmatites and in placer deposits.
Although Hafnon is not a well-known mineral, it often occurs together with Zircon rich in hafnium, and is thus an ore of the rare metal hafnium.
Hafnon occurs in every locality where there exists hafnium-rich Zircon. Since Hafnon is almost identical in physical and chemical properties to Zircon, it is rarely distinguished from it. The type locality for Hafnon is Alto Ligonha, Zambezia Province, Mozambique, where it has been found at several pegmatites at the Muiane Mine. Chestnut-colored Hafnon crystals have been found in the Naque region in Minas Gerais, Brazil.
Distingushing Similar Minerals
Zircon - Cannot be identified without complex tests.
Vesuvianite - Softer (6½), lighter in weight.
Cassiterite - Heavier, softer.
Spinel - Occurs in octahedral crystals, lighter in weight (3.5 - 4.1).