Almandine and Smoky Quartz

Sample of several red/brown subhedral dodecahedrons of Almandine crystals embedded on the substrate with small, subhedral prismatic Quartz crystals that are terminated by double rhombohedrons. Vitreous lustre and faint striations visible on the Quartz crystals. Average Almandine crystal size: 0.9 cm x 0.8 cm x 0.7 cm. Average Quartz crystal size: 0.7 cm x 0.4 cm x 0.4 cm. Almandine (Fe3Al2Si3O12) is part of the Garnet group, specifically the aluminum silicates. Almandine can be deep red to brown or brownish black in colour. Lustre is vitreous and streak is colourless. Hardness is 6 1/2 to 7 1/2. Garnet usually occurs as dodecahedrons or trapezohedrons but can also be granular, lamellar or compact. Quartz (SiO2) has a large variety of colours and when it is pale brown to black it is known as Smoky Quartz. Lustre can be vitreous or greasy and streak is white. Hardness is 7. Quartz usually occurs as long or short prismatic crystals that are terminated by double rhombohedrons and have striations crosswise. Quartz can also be granular, massive or disseminated.