English | Български
Where am I? > Home > Classification > Sapphirine

Quick navigation selector


Class: Silicates
Group: Aenigmatite

In high-temperature metamorphic rocks or xenoliths with abundant aluminium and magnesium and low silicon; may occur as a primary magmatic mineral in subsilicic rocks (Anthony et al., 2001—2005). Very rare as faceted specimens.

Original description: ‘Saphirin’ Stromeyer, F., 1819. 2. Saphirin von Fiskenaes oder Kikertarsoeitsiak — Göttingische gelehrte Anzeigen 3: 1994—1995 [view in ‘Library’].

Type locality: Fiskenaes old harbour, Fiskenaes, Nuuk, Sermersooq, Greenland.

Type material: unknown.

Etymology: for its sapphire-like colour.

Distribution: Canada: at Wilson Lake, Labrador; Germany: from Waldheim, Saxony; Greenland: Fiskenaes; Italy: Piedmont; Madagascar; South Africa: Transvaal; Tanzania (Anthony et al., 2001—2005).



Essential elements: oxygen (O), magnesium (Mg), aluminium (Al), silicon (Si).

Crystal data

Crystallography: monoclinic — prismatic or triclinic — pinacoidal. Crystal habit: crystals indistinct, tabular on {010}, to 3 cm; commonly as disseminated grains or aggregates. Twinning: repeated on {010}; uncommon (Anthony et al., 2001—2005).

Physical properties

Cleavage: fair on {010}, poor on {001}, {100} (Anthony et al., 2001—2005). Fracture: subconchoidal (Anthony et al., 2001—2005). Tenacity: no data. Hardness: 7.5 (Arem, 1987: 165). Density: 3.4—3.58 g/cm3 (Lazzarelli, 2012). Luminescence: none (Arem, 1987: 166).

Optical properties

Colour: light to dark blue or green, white, grey, pale red, yellow; in thin section, colourless to blue or pink (Anthony et al., 2001—2005). Diaphaneity: transparent to translucent (Anthony et al., 2001—2005). Lustre: vitreous (Arem, 1987: 165). Refractive index: 1.701—1.724 — anisotropic [biaxial (-)] (Lazzarelli, 2012). Birefringence: 0.005—0.007. Dispersion: 0.019. Pleochroism: X = colourless, pale reddish, yellowish green, pale yellow; Y = sky-blue, bluish green; Z = blue, dark blue (Anthony et al., 2001—2005).

Material from ‘Repository’

2 specimens: 0052 — 0.10 ct, Sri Lanka; 0581 — 0.06 ct, Sri Lanka.

Gallery view