HAFNON
hafnon - mineral 51.5.2.2

	Chemical Formula	HfSiO4
	Composition	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, it is scientifically a different mineral, Zircon.
	Variable Formula	(Hf,Zr)SiO4 ; (Hf,Zr,U,Th,Y)SiO4
	Color	Gray, brown, black
	Streak	Colorless
	Hardness	7½. When impure can be as low as 6½.
	Crystal Forms and Aggregates	(Tetragonal) Occurs in the same crystal habits as Zircon, but rarely in large crystals like Zircon.
	Transparency	Translucent to opaque
	Specific Gravity	6.97
	Luster	Greasy to adamantine. Radioactive Hafnon has a pitchy luster.
	Cleavage	3,2
	Fracture	Conchoidal to uneven
	Tenacity	Brittle
	In Group	Silicates ; Nesosilicates
	All About	Hafnon is isomorphous with the mineral Zircon. It is 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.
	Uses	Although Hafnon is not a well-known mineral, it often occurs together with Zircon rich in hafnium, thus Hafnon is an ore of hafnium.
	Striking Features	Crystal shape and weight
	Popularity (1-4)	3
	Prevalence (1-3)	3
	Demand (1-3)	3
	Distinguishing Similar Minerals	Zircon - cannot be identified without complex tests Vesuvianite - softer (6½), lighter in weight Cassiterite - heavier Spinel - occurs in octahedral crystals, lighter in weight (3.5 - 4.1)
	Commonly Occurs With	Zircon, Monazite, Xenotime, Albite, Quartz, Biotite, Orthoclase, Nepheline
	Noteworthy Localities	There are no actual localities worthy of documentation where Hafnon can be collected as a specimen on its own. Hafnon occurs in every locality in which there exists hafnium-rich Zircon, and since it is almost identical in physical and chemical properties to Zircon, it is rarely distinguished from the Zircon.
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Additional references

• The Mineral Gallery (Amethyst Galleries)
• Mineralogy Database (David Barthelmy)