Zinc Minerals

Zinc minerals are well known among rock and mineral collectors but not every rockhound is aware of the varieties. So, I decided to put together a list of Zinc minerals plus give you a little background on the metal, what it is used for, and where it is mined.

If you haven’t started collecting Zinc minerals then I’d add them to your shopping list before you attend the next rock and mineral show.

 

Is Zinc A Metal?

Zinc is a lustrous, bluish-white metal that is listed on the periodic table. It’s brittle and crystalline at ordinary and average temperatures but becomes ductile and malleable when heated between 230 and 302℉. This fairly reactive metal combines with oxygen and other nonmetals and will react with dilute acids to release hydrogen.

 

What Are Zinc Minerals Used For?

Zinc minerals are used principally for galvanizing other metals, like iron because it prevents rusting. Over 50% of metallic Zinc goes into galvanizing Steel, but it’s also essential in preparing certain alloys. It’s used for the negative plates in some electric batteries, gutters, roofing, and other areas of building construction.

I bet you didn’t know that Zinc is the primary metal used in making pennies in America. It’s also used in the automobile industry for die-casting.

If you’re an artist or like to paint then you’re a consumer of Zinc Oxide because it’s used as the white pigment in watercolors or paints.

As a pigment, Zinc is used in cosmetics, plastics, wallpaper, printing ink, photocopier paper, and more. In rubber production, its key role is to act as a catalyst during manufacturing and as a heat disperser in the final products.

 

Zinc Formula

Zn is the formula for Zinc.

This element is a low-melting metal of the periodic table’s Group 12 (IIb). It’s essential to life and is one of the most widely used metals on the planet.

Zinc’s atomic number is 30, and it has an atomic weight of 65.39. While heating it between 230 and 302℉ causes the metal to become ductile and malleable it doesn’t actually melt until you reach 788℉.

 

Where Is Zinc Found?

Zinc is found in various locations around the world. According to the United States Geological Survey, the world’s Zinc reserves were estimated at roughly 250 million tonnes in 2021 with Australia, China, Mexico, Peru, and Russia among the nations with the largest reserves. Canada came in ninth with 5.4 million tonnes.

There are several locations where Zinc is mined in the US, including Alaska and Tennessee.

 

Types of Zinc Minerals You Can Collect

 

 

Sphalerite

This is one of those stones where you can find amazing specimens and facet-grade rough. If you come across a faceted piece of Sphalerite you’ll notice it has high dispersion. Specimens on the other hand will exhibit small clusters of crystals or larger single crystals on matrix. Most Sphalerite comes in Yellow, Light to Dark Brown, Black, Reddish Brown, light Blue, Pale Green, Greenish Yellow, and Colorless.

 

 

Smithsonite

Fairly popular Zinc mineral because you can source it a rock and minerals hows and a nice specimen won’t break the bank. You’ll notice the cool-looking botryoidal clusters on top of matrix.

 

 

Zincite

If you’re walking around a gem show then Zincite is sure to catch your eye with its reddish-orange color and the needle-like crystals. Most of this material is taken from a smelting facility that dealt with Zinc. These crystals grew on the inside of the smoke stacks.

 

Physical Properties of Zinc

Zinc is a bluish-white metal with a metallic luster and a hardness of 2.

The crystal structure of Zinc is hexagonal.

Transparency will be opaque and a streak test will produce a greyish streak

Tenacity will be brittle while the cleavage plane will be perfect.

To the untrained eye, a chunk of Zinc could easily be mistaken as silver, especially if it’s been treated.

 

How Was Zinc Discovered?

While Zinc compounds have been used for at least 2,500 years, the mineral wasn’t recognized as a distinct element until much later. Metallic Zinc was first produced in India sometime around the 1400s.

In 1764 Zinc was rediscovered by Andreas Sigismund Marggraf, which was done by heating Calamine with charcoal.

Metallic Zinc may have appeared much later in history than other common metals. Still, there is evidence that the Greeks know about its existence. However, the Greeks called it pseudargyras or ‘false silver’; they simply didn’t have a method of producing Zinc in quantity.

Looking back, the Romans produced considerable amounts of Zinc, Copper, alloy, and brass as early as 200 BCE. Their process included heating a mixture of charcoal and Zinc oxide in crucibles covered with lumps of metallic Copper.