Na8Al6Si6O24 Cl2 La sodalite est très répandue au mont Saint-Hilaire, étant l’un des principaux éléments de la syénite à sodalite. Elle est fluorescente en orange vif à rouge-orangé sous courte et grande longueur d’onde. De plus, elle présente une phosphorescence blanc-jaunâtre…
Acanthite
Ag2S Acanthite is a rare mineral at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color is usually black. Luster is metallic. Diaphaneity is opaque. Crystal System is monoclinic; P21/n. Crystal Habits a flat acicular crystals to 2mm. Cleavage: {001} is indistinct. Fracture is subconchoidal. Hardness is 2 – 2.5 Specific Gravity is approximately…
Actinolite
Ca2(Fe2+,Mg)5(Si8O22)(OH)2 Member of the amphibole group, actinolite is rare at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color ranges from dark green to black. Luster is vitreous. Diaphaneity is transparent to translucent. Crystal System is monoclinic;C2/m. Crystal Habits include acicular crystals to 5mm. Cleavage: {001} is perfect. Fracture is uneven…
Aegirine
NaFe3+Si2O6 Aegirine, a member of the pyroxene group, is one of the most abundant and conspicuous crystallized minerals occurring at Mont Saint-Hilaire. It is a major constituent in the pegmatites and occurs in varying degrees of abundance in most of…
Andesine
NaAlSi3O8 Andesine is relatively rare at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color is usually grey or green. Luster is vitreous. Diaphaneity is transparent to translucent. Crystal System is triclinic; P1. Crystal Habits include phenocrysts. Cleavage: {001} is perfect and {010} is good. Fracture is conchoidal to uneven. Hardness is 6…
Anglesite
PbSO4 Anglesite occurs as an extremely rare secondary mineral at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color is usually green or tan. Luster is adamantine to earthy. Diaphaneity is translucent to opaque. Crystal System is orthorhombic; Pnma. Crystal Habits include thin crusts on galena and tiny sharp pseudo-rhombohedra.…
Anorthoclase
(Na,K)AlSi3O8 Anorthoclase is another rare mineral species at MSH. PHYSICAL CHARACTERISTICS: Color is usually grey (mottled). Luster is vitreous to pearly on cleavage areas. Diaphaneity is transparent to translucent. Crystal System is triclinic; C. Crystal Habits include phenocrysts. Cleavage: {001} is perfect and {010} is good. Fracture is…
Antimony
Sb Antimony is extremely rare at MSH. PHYSICAL CHARACTERISTICS: Color is usually dark grey. Luster is sub-metallic. Diaphaneity is opaque. Crystal System is hexagonal; R3m. Crystal Habits include irregular grains. Cleavage: {0001} is perfect. Fracture is not observed. Hardness is 3 – 3.5 Specific Gravity is approximately 6.7 g/cm3. Streak is…
Aragonite
CaCO3 Aragonite, a member of the aragonite group, is extremely rare at MSH. PHYSICAL CHARACTERISTICS: Color varies from colorless to white and pinkish yellow. Luster is vitreous to resinous. Diaphaneity is transparent to translucent. Crystal System is orthorhombic; Pmcn. Crystal Habits include aggregates of tabular crystals…
Arsenopyrite
FeAsS Arsenopyrite is a relatively rare mineral at MSH PHYSICAL CHARACTERISTICS: Color is usually silver-white. Luster is metallic. Diaphaneity is opaque. Crystal System is monoclinic; P21/c. Crystal Habits include the very sharp wedge-shaped crystals to 3mm and short prismatic crystals; crystalline masses. Cleavage {001} is distinct. Fracture is…
Augite
(Ca,Mg,Fe2+,Fe3+,Al,Ti)2(Al,Si)2O6 Augite is extremely rare at MSH. A single crystal had been found and is now lost. Any information on this species from MSH would be appreciated. PHYSICAL CHARACTERISTICS: Color is brown green, green, light brown, dark brown, black. Luster is vitreous…
Barite
BaSO4 Barite is a rare accessory mineral at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color varies from colorless to pale, lemon or bright yellow. Luster is vitreous. Diaphaneity is transparent. Crystal System is orthorhombic; Pnma. Crystal Habits include well-formed short prisms to 2mm, complex tabular to equant crystals…