Teallite is a sulfide mineral of tin and lead with chemical formula: PbSnS₂. It occurs in hydrothermal veins and is sometimes mined as an ore of tin. Teallite forms soft silvery grey mica-like plates and crystallizes in the orthorhombic system. The Mohs hardness is 1.5 to 2 and the specific gravity is 6.4.

Teallite
General
Category	Sulfide minerals
Formula (repeating unit)	PbSnS2
IMA symbol	Tel[1]
Strunz classification	2.CD.05
Crystal system	Orthorhombic
Crystal class	Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Space group	Pbnm (no. 62)
Unit cell	a = 4.26 Å, b = 11.41 Å c = 4.09 Å; Z = 2
Identification
Color	Silvery gray, lead-gray to iron-gray; tarnishes dull or iridescent
Cleavage	{001} perfect (lamellar cleavage); flexible
Tenacity	Malleable
Mohs scale hardness	1+1⁄2 – 2
Luster	Metallic
Streak	Black
Diaphaneity	Opaque
Specific gravity	6.36
Optical properties	Anisotropic
Pleochroism	Weak
References	[2][3]

Teallite was first described in 1904 from its type locality in Santa Rosa, Antequera, Bolivia. It was named for the British geologist Jethro Justinian Harris Teall (1849–1924).^[4]