K(Fe2+,Mg)3(AlSi3O10)(OH,F)2 Biotite, one of the several members of the mica group found at MSH is fairly abundant in many environments and as a rock-forming mineral. It is difficult to distinguish from annite. PHYSICAL CHARACTERISTICS: Color is usually dark red brown to…
Bismuth
Bi Bismuth is extremely rare at Mont Saint-Hilaire, only a few specimens have been recovered. PHYSICAL CHARACTERISTICS: Color is usually silver-white. Luster is metallic. Diaphaneity is opaque. Crystal System is hexagonal; R3m Crystal Habits include small flakes and blebs to 1mm. Cleavage {001} is perfect, {101} is…
Brochantite
Cu4(SO4)(OH)6 Brochantite is relatively rare at MSH. PHYSICAL CHARACTERISTICS: Color is usually red. Luster is dull. Diaphaneity is opaque. Crystal System is monoclinic; P21/a. Crystal Habits include altered red masses. Cleavage not observed. Fracture is uneven to conchoidal. Hardness is 3.5 – 4. Specific Gravity is approximately 3.97 g/cm3. Streak is…
Calcite
CaCO3 At Mont Saint-Hilaire, one can find excellent crystals of calcite in several habits. PHYSICAL CHARACTERISTICS: Color ranges from colorless (very common) to beige, pale brown, pale green and yellow (pale to lemon; the most common color). Luster is vitreous. Diaphaneity is transparent…
Cerussite
PbCO3 Cerussite is an extremely rare secondary mineral at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color varies from white to off-white. Luster is adamantine to vitreous. Diaphaneity transparent to translucent. Crystal System is orthorhombic; Pmcn. Crystal Habits include acicular crystals to 0.5mm and as thin crusts on galena.…
Celestine
Na26REE6(SiO3)6(PO4)6(CO3)6(S4+O2)O Celestine is extremely rare at Mont Saint-Hilaire and is hard to distinguish visually. PHYSICAL CHARACTERISTICS: Color varies from white to tan. Luster is dull. Diaphaneity is transparent to translucent. Crystal System is orthorhombic; Pbnm. Crystal Habits include compact spherical aggregates to 1mm. Cleavage {001} is perfect,…
Chalcopyrite
CuFeS2 Chalcopyrite is a rare mineral at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color is brass-yellow, sometimes with iridescence. Luster is metallic. Diaphaneity is opaque. Crystal System is tetragonal; I42d. Crystal Habits include sharp disphenoids to 2 – 3mm and as embedded masses. Cleavage {011} is distinct. Fracture is uneven.…
Diopside
CaMgSi2O6 Diopside, a member of the pyroxene group, is quite rare at MSH. PHYSICAL CHARACTERISTICS: Color is usually pale green; pale pink on the tabular crystals. Luster is vitreous. Diaphaneity is transparent to opaque. Crystal System is monoclinic; C2/c. Crystal Habits include masses of small prisms…
Clinochlore
(Mg,Fe2+)5Al(Si3Al)O10(OH)9 Clinochlore, a member of the chlorite group, is found in marble xenoliths at Mont Saint-Hilaire. PHYSICAL CHARACTERISTICS: Color is usually colorless, tan or brown. Luster is vitreous. Diaphaneity is translucent to opaque. Crystal System is monoclinic; C2/m. Crystal Habits include aggregates of minute plates forming…
Aégirine FR
NaFe3+Si2O6 L’aégirine, membre du groupe des pyroxènes, est une des espèces les plus communes et visibles du mont Saint-Hilaire. Elle est une constituante majeure des pegmatites et on la retrouve dans la plupart des autres associations minérales. Les cristaux vont…
Dolomite
CaMg(CO3)2 Dolomite is common at MSH. Its hexagonal crystals display some interesting color zoning, with alternating colorless and yellow or light and dark brown zones. PHYSICAL CHARACTERISTICS: Color ranges from white to pale pink to beige brown, pale to apple-green and…
Albite
NaAlSi3O8 L’albite, un membre des feldspaths, est l’une des espèces les plus communes. On la retrouve sous forme de cristaux lamellaires bien formés jusqu’à quelques centimètres de longueur. Quelques fois elle est incluse dans la rhodochrosite, l’elpidite et d’autres minéraux.…