Pyroxene Group Minerals

LiAlSi2O6 Origin of Name : From the Greek word spodoumenos, meaning “ashes.” Hand Specimen Identification Spodumene is typically found in pegmatites where it may  form very large crystals. Prismatic cleavage,hardness, color, and association help identify it, but it may be difficult to tell from feldspar or scapolite. it often has …

Hand Specimen identification: Spodumene is typically found in pegmatites where it may form very large crystals. Prismatic cleavage, hardness, color, and association help identify it, but it may be difficult to tell from feldspar or scapolite. it often has the appearance of a log or of petrified wood. Chemical Composition …

Hand Specimen identification: Association, form, two cleavages at 86° to each other, and color identify diopside . It may be confused with other pyroxenes or with hornblende, but the latter has two cleavages at 60° to each other. Diopside may contain substantial Fe, Al, or other impurities; exact composition cannot …

Hand Specimen identification: Occurrence as phenocrysts in volcanic rock, form, two cleavages at 86°, and color identify pyroxene, but telling pigeonite from the other dark-colored pyroxenes is difficult. Only X-ray studies can make the distinction. Chemical Composition : (Ca,Mg,Fe)2Si2O6 Hardness : 6 Specific Gravity3.4 Cleavage/Fracture : two perfect prismatic {110}/uneven …

Hand Specimen identification: Association, form, two cleavages at 86° to 87°, and color identify pyroxene, but differentiating augite is problematic without X-ray data. White to green or pale green pyroxenes are often diopside; augite tends to be dark green or black. Augite is occasion-ally confused with hornblende. Plate 6.1 is …

Hand Specimen identification: Association, luster, color, and two cleavages at about 90° to each other identify pyroxene, but distinguishing enstatite from other pyroxenes can be problematic. Exact composition cannot be determined without additional analytical data. It may also be confused with amphibole, but the latter has two cleavages at about …

Hand Specimen identification: Association with other high-pressure minerals, form, two (rarely seen) cleavages at near 90°, green color, and tenacity identify jadeite. It is distinguished from nephrite by its luster. An optical microscope may be needed to confirm identification. Chemical Composition : NaAlSi2O6 Hardness : 61 2 to 7 Specific …