The mineral petzite, Ag

Silver

Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

₃Au

Gold

Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

Te₂, is a soft, steel-gray telluride mineral

Telluride mineral

A telluride mineral is a mineral that has the telluride anion as a main component.Tellurides are similar to sulfides and are grouped with them in both the Dana and Strunz mineral classification systems.Examples include:* calaverite* hessite* rickardite...

 generally deposited by hydrothermal activity. It forms isometric crystals

Cubic crystal system

In crystallography, the cubic crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals....

, and is usually associated with rare tellurium and gold

Gold

Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

 minerals, often with silver

Silver

Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

, mercury

Mercury (element)

Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

, and copper

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

.

The name comes from chemist W. Petz, who first analyzed the mineral from the type locality

Type locality (geology)

Type locality , also called type area or type locale, is the where a particular rock type, stratigraphic unit, fossil or mineral species is first identified....

 in Săcărâmb, Transylvania

Transylvania

Transylvania is a historical region in the central part of Romania. Bounded on the east and south by the Carpathian mountain range, historical Transylvania extended in the west to the Apuseni Mountains; however, the term sometimes encompasses not only Transylvania proper, but also the historical...

, Romania

Romania

Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

 in 1845.

It occurs with other tellurides in vein

Vein (geology)

In geology, a vein is a distinct sheetlike body of crystallized minerals within a rock. Veins form when mineral constituents carried by an aqueous solution within the rock mass are deposited through precipitation...

 gold deposits. It is commonly associated with native gold, hessite

Hessite

Hessite is a mineral form of disilver telluride . It is a soft, dark grey telluride mineral which forms monoclinic crystals.It is named after Germain Henri Hess ....

, sylvanite

Sylvanite

Sylvanite or silver gold telluride, Te2, is the most common telluride of gold.-Properties:The gold:silver ratio varies from 3:1 to 1:1. It is a metallic mineral with a color that ranges from a steely gray to almost white. It is closely related to calaverite, which is more purely gold telluride with...

, krennerite

Krennerite

Krennerite is an orthorhombic gold telluride mineral which can contain a relatively small amount of silver in the structure. The formula is AuTe2 varying to Te2. Both of the chemically similar gold-silver tellurides, calaverite and sylvanite are in the monoclinic crystal system, whereas krennerite...

, calaverite

Calaverite

Calaverite, or gold telluride, is an uncommon telluride of gold, a metallic mineral with the chemical formula AuTe2, with approximately 3% of the gold replaced by silver. It was first discovered in Calaveras County, California in 1861, and was named for the county in 1868.The mineral often has a...

, altaite

Altaite

Altaite, or lead telluride, is a yellowish white mineral with an isometric crystal structure. Altaite is in the galena group of minerals as it shares many of properties of galena. Altaite has an unusually high density for a light-colored mineral...

, montbrayite, melonite

Melonite

Melonite is a telluride of nickel; it is a metallic mineral. Its chemical formula is NiTe2. It is opaque and white to reddish-white in color, oxidizing in air to a brown tarnish....

,
frohbergite, tetradymite

Tetradymite

Tetradymite is a mineral consisting of bismuth, tellurium and sulfide, Bi2Te2S, also known as telluric bismuth. If sulfur is absent the mineral is tellurobismuthite and the formula is then Bi2Te3...

, rickardite

Rickardite

Rickardite is a copper telluride mineral . It occurs in Colorado, USA.-References:*D. M. Chizhikov and V. P. Shchastlivyi, 1966, Tellurium and Tellurides, Nauka Publishing, Moscow-External links:**...

, vulcanite

Vulcanite

Vulcanite is a rare copper telluride mineral. The mineral has a metallic luster, and is a green or bronze-yellow shade. It has a hardness between 1 and 2 on the Moh's scale . Its crystal structure is orthorhombic....

 and pyrite

Pyrite

The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...

.