Tintinaite

Chemical formula: Pb₂+₁₀Cu₁+₂Sb₃+₁₆S₂-₃₅

Tintinaite is a rare sulfosalt mineral, a lead-copper variety of kobellite, occurring as acicular or fibrous aggregates.

## Characteristics Tintinaite is a rare sulfosalt mineral, classified as a lead-copper variety of kobellite. It typically forms aggregates of acicular, capillary, or fibrous crystals, which can be tangled into dense, felt-like masses. Less commonly, it occurs in radial or granular forms. Individual crystals are elongated and often exhibit longitudinal striations. Its color ranges from steel-gray to black, with a distinct metallic luster. ## Physical Properties This mineral is characterized by a hardness of 2.5-3 on the Mohs scale, meaning it is relatively soft. It has a metallic luster and is opaque. Its density is quite high, approximately 6.3 g/cm³. It is a brittle mineral. ## Colors and Varieties Tintinaite occurs in uniform colors from steel-gray, through tin-white, to black. Over time, its surface may dull or develop a patina. No distinct color varieties or commercial forms are recognized. ## History and Name The mineral's name comes from its type locality – the Tintina Valley in Yukon, Canada, where it was discovered. It was described and recognized as a new mineral species in 1968 by D.C. Harris, J.L. Jambor, G.R. Lachance, and R.I. Thorpe. Initially considered a distinct species, later studies by the International Mineralogical Association (IMA) in 2008 reclassified it as a copper- and lead-rich variety of kobellite. ## Uses Tintinaite has no industrial applications. It is solely an object of interest for collectors of rare minerals and scientists studying sulfosalts.

Properties

Mohs hardness: 2.5-3
Luster: Metallic
Streak: Black
Density: 6.3
Cleavage: Good on {010}
Fracture: Uneven
Transparency: Opaque
Crystal system: Orthorhombic

Diagnostic features

## Identification Tintinaite can be identified by its characteristic felt-like or acicular aggregates of steel-gray color and metallic luster. A helpful feature is its low hardness and its co-occurrence with other lead sulfides and sulfosalts in hydrothermal veins. ## Distinguishing from Similar Minerals Tintinaite is visually almost identical to kobellite, and distinguishing between them requires chemical analysis (EDS/WDS) to determine the copper-to-iron ratio. It can also be confused with other acicular sulfosalts, such as jamesonite, boulangerite, or zinkenite. Distinguishing from these often also requires advanced analytical methods, although jamesonite and boulangerite tend to be more "flexible" and have excellent cleavage in one direction, while tintinaite aggregates are usually rigid and brittle. ## Crystal Forms This mineral forms acicular, capillary, or fibrous crystals, typically up to several millimeters long. These crystals combine into tangled, felt-like masses, as well as radial and radiating-fibrous aggregates. Granular aggregates are less common.

Geological environment

## Genesis Tintinaite is a mineral of hydrothermal origin. It forms in medium- to high-temperature ore veins rich in antimony, lead, and sulfur. It forms in paragenesis with other sulfides and sulfosalts. ## Mineral Associations This mineral often co-occurs with other lead sulfosalts, such as kobellite, boulangerite, and jamesonite. It is also accompanied by galena, pyrite, sphalerite, arsenopyrite, chalcopyrite, tetrahedrite, as well as quartz and carbonates (siderite, ankerite). ## Localities The most important and classic locality, being the type locality, is the Tintina Valley in Yukon, Canada. Other known localities worldwide include the Săcărâmb mine in Romania; Vena-Gruvan and other mines in the Bergslagen area in Sweden; some localities in the Czech Republic (e.g., Kutná Hora) and Slovakia; and silver mines in Idaho in the USA.

Rarity

Rare

For collectors

## Quality Criteria Most valued by collectors are specimens with well-formed, rich, tangled aggregates of acicular crystals, forming dense "felts" on the rock matrix. Contrast with bright quartz or other associated minerals enhances the specimen's attractiveness. The size and abundance of tintinaite aggregates are also important. ## Popular Localities Specimens from the type locality in Yukon (Canada) and from the historic Săcărâmb mine in Romania are the most classic and sought after by collectors. Good quality material also comes from Swedish mines in Bergslagen.

Care and storage

## Cleaning Tintinaite specimens should be cleaned very carefully, preferably using compressed air to remove dust from delicate, acicular crystals. For more stubborn dirt, a soft brush and distilled water can be used, followed by immediate and thorough drying of the specimen. Ultrasonic cleaners should be avoided, as they can damage brittle aggregates. ## What to Avoid Contact with acids and other chemicals that may react with sulfides should be avoided. The mineral is sensitive to impact and abrasion due to its low hardness and brittleness. Prolonged exposure to moisture can lead to slow oxidation and dulling of the surface. ## Storage It is recommended to store tintinaite specimens in closed, padded collector boxes to protect them from mechanical damage and dust. Avoid storing it with harder minerals that could scratch it. Due to its fibrous nature, specimens should be protected from vibrations.

Sources

IMA Mineral List (CNMNC)