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9 Apr 2024: Orthopyroxene. Orthopyroxene crystal structure, CrystalMaker. Orthopyroxene chemical variability. Enstatite (common in mafic rocks) always has high Mg and low Ca. Formula. (Mg,Fe). 2. Si. 2. O. 6. Structure. Chain silicate. Crystal System. Crystal

9 Apr 2024: Alkali Feldspar. Alkali feldspar hand specimen, pink hue. Alkali feldspar hand specimen, milky white. Simply twinned alkali feldspar in granite. Alkali feldspar unit cell, CrystalMaker. Formula. (K,Na)[AlSi. 3. O. 8. ]. Structure. Framework

9 Apr 2024: Clinopyroxene (augite). Phase diagram deomstrating the chemical compositional range for clinopyroxenes. Formula. (Ca,Mg,Fe. 2+. ,Fe. 3+. ,Ti,Al). 2. [(Si,Al). 2. O. 6. ]. Structure. Chain silicate. Crystal System. Crystal system: monoclinic ().

2 Jun 2024: Search site. Publications. Uploading Images. Members of the Department can attach an image to a publication by clicking on the title of the publication in the listing below. Please note: all images attached to a publication will be visible on

9 Apr 2024: Alteration. Zonation. Accessory minerals:. - Sphene. - Magnetite. - Apatite. Rock History.

9 Apr 2024: Browse Items (264 total). Page. of 27. Sort by:. Formula NaCl Structure Non-silicate Crystal System Crystal system: cubic Physical Properties Colour in hand specimen: colourless or white when pure, more typically orange or red due to inclusions of

9 Apr 2024: Some areof magnetite, clinopyroxene and other minerals. Extensive alteration along abundant cracks. ... Groundmass. - Fine-grained. Plagioclase feldspar needles, clinopyroxene, some olivine (mostly altered), and opaques, probably magnetite.

9 Apr 2024: The olivine has decomposed to magnetite and serpentine. Relict olivine grains display characteristic curving cracks andClinopyroxene (augite). - ... Some simple twinning. Accessory minerals. - Opaque, interstitial, probably magnetite. Rock History.

9 Apr 2024: The olivine has decomposed to magnetite and serpentine. Relict olivine grains display characteristic curving cracks andClinopyroxene (augite). - ... Some simple twinning. Accessory minerals. - Opaque, interstitial, probably magnetite. Rock History.

9 Apr 2024: Some areof magnetite, clinopyroxene and other minerals. Extensive alteration along abundant cracks. ... Groundmass. - Fine-grained. Plagioclase feldspar needles, clinopyroxene, some olivine (mostly altered), and opaques, probably magnetite.

9 Apr 2024: Mica, biotite. hand specimen of biotite mica. Crystals of bioitie mica with perfect basal cleavage. Biotite sheet silicate crystal structure, CrystalMaker. Formula. K. 2. (Mg,Fe. 2+. ). 6-4. (Fe. 3+. ,Al,Ti). 0-2. [Si. 6-5. Al. 2-3. O. 20. ](OH,F).

9 Apr 2024: Bottryoidal hematite crystal. Hematite crystal strucutre, CrystalMaker. Formula. Fe. 2. O. 3. Structure. Non-silicate. Crystal System. Crystal system: trigonal (-). Physical Properties. Colour in hand specimen: black, steel-grey and bright to dull

9 Apr 2024: Minerals. Rocks comprise minerals. In order to understand the paragenesis of a rock, be it igneous, sedimentary or metamorphic, we must identify its constituent minerals. The aim of this collection is to detail the structural, physical and optical

9 Apr 2024: Browse Items (264 total). Page. of 27. Sort by:. Compare with phenocryst. Formula Fe3O4 Structure Non-silicate Crystal System Crystal system: cubic Physical Properties Colour in hand specimen: blackStreak: blackCleavage: noneHardness: 7.5-8 Optical

9 Apr 2024: Browse Items (264 total). Page. of 27. Sort by:. Formula (K,Na)[AlSi3O8] Structure Framework silicate Crystal System Crystal system: monoclinic (-) or triclinic () (-) Physical Properties Colour in hand specimen: white or pink Cleavage: two at 90

25 Apr 2024: We also work with Rich Harrison, making 3D reconstructions of magnetite and other nanoparticles, which have interesting magnetic properties as well as being tracers of particulate air pollution.

9 Apr 2024: Browse Items (264 total). Page. of 27. Sort by:. Formula Fe3O4 Structure Non-silicate Crystal System Crystal system: cubic Physical Properties Colour in hand specimen: blackStreak: blackCleavage: noneHardness: 7.5-8 Optical Properties Colour in

9 Apr 2024: Browse Items (7 total). Tags: igneous. Sort by:. Formula (Na,K)0-1Ca2(Mg,Fe2+,Fe3+,Al)5Si6-7.5Al2-0.5O22(OH)2 Structure Chain silicate Crystal System Crystal system: monoclinic () (-) Physical Properties Colour in hand specimen: black Cleavage:

9 Apr 2024: Browse Items (7 total). Tags: igneous. Sort by:. Formula (Na,K)0-1Ca2(Mg,Fe2+,Fe3+,Al)5Si6-7.5Al2-0.5O22(OH)2 Structure Chain silicate Crystal System Crystal system: monoclinic () (-) Physical Properties Colour in hand specimen: black Cleavage:

9 Apr 2024: Browse Items (7 total). Tags: igneous. Sort by:. Formula SiO2 Structure Framework silicate Crystal System Crystal system: trigonal () Physical Properties Colour in hand specimen: colourless Lustre: vitreous Pleochroism: none Cleavage: