Igneous Rocks

+ward’ssciencewardsci.com800-962-2660 Tuff Type: Igneous; extrusive (pyroclastic). Texture/Appearance: Clastic texture with angular rock and mineral fragments and lapilli mixed with fine-grained volcanic ash, partly cemented by sedimentary materia...

PDF

wardsci.com 800-962-2660 Peridotite Type: Igneous; intrusive. Texture/Appearance: Medium to coarse-grained; massive, granular, sometimes porphyritic. Color: Medium gray to greenish-gray. Mineralogy/Chemistry: Ultramafic, with mafic minerals greate...

PDF

wardsci.com 800-962-2660 Topaz Al2SiO4 (F,OH)2 Crystallography: Orthorhombic; 2/m2/m2/m. Crystals commonly prismatic with vertical prism faces often striated; also in crystalline masses or granular. Physical Properties: Cleavage: {001} perfect. Fr...

PDF

ward’s sciencewardsci.com800-962-2660 Hornfels Type: Metamorphic, regional. Texture/Appearance: Homogeneous; dense, fine-grained. Granoblastic; may have porphyroblasts or any of the minerals present. Color: Varies; light to dark. May be pink, brow...

PDF

ward’s sciencewardsci.com800-962-2660 Corundum Al2O3 Crystallography: Hexagonal-R; 32/m. Crystals commonly tabular on {0001} or prismatic {1120}; often rude barrel-shaped crystals. Usually massive; coarse or fine granular. Physical Properties: Cle...

PDF

wardsci.com 800-962-2660 Marble Type: Metamorphic; regional and contact. Texture/Appearance: Fine to coarse-grained; granoblastic to saccharoidal. May appear patched or with streaks or banding that is deformed. Color: Variable, commonly white, pin...

PDF

wardsci.com 800-962-2660 Pyrrhotite Fe1-xS (x = 0 - 0.17) Crystallography: Monoclinic; 2/m (below about 250°C). Hexagonal; 6/m3/m2/m for high tempera- ture forms. Crystals rare, usually tabular to platy on {0001}. Also massive, granular. Physical ...

PDF

1 All About Elements: Lithium https://wardsci.com/store wardsci.com | 800-962-2660 2 3 Fun Facts About… Lithium 1. Elemental lithium can float in mineral oil. 2. Lithium was one of the elements produced during Big Bang Nucleosynthesis. The other t...

PDF

wardsci.com 800-962-2660 Forsterite Mg2 Si O4 (Olivine Group) Crystallography: Orthorhombic; 2/m2/m2/m. Rarely in small equidimensional or tabular crystals; usually in granular masses and as rounded grains. Physical Properties: Cleavage: {101} ind...

PDF

+ward’ssciencewardsci.com800-962-2660 Pumice Type: Igneous; extrusive (pyroclastic). Texture/Appearance: Glassy, vesicular, foamy, frothy. Very light-weight with numerous vacuoles (some varieties float in water). A natural glass froth in which the...

PDF

ward’s sciencewardsci.com800-962-2660 Gabbro Type: Igneous; intrusive. Texture/Appearance: Granular; medium-grained. Color: Dark, medium gray, green-gray or brownish-gray. Mineralogy/Chemistry: Mafic; with essential plagioclase (50%-75%) and pyrox...

PDF

ward’s sciencewardsci.com800-962-2660 Syenite Type: Igneous; intrusive. Texture/Appearance: Massive; medium to coarse-grained, often changing to pegmatitic. Appears speckled with dark patches, sometimes porphyritic; may show flowage. Color: Pale, ...

PDF

+ward’ssciencewardsci.com800-962-2660 Obsidian Type: Igneous; extrusive Texture/Appearance: Glassy with rare microphenocrysts or spherulites; conchoidal fracture. Color: Shiny black to brown. Mineralogy/Chemistry: A natural glass or rhyolitic (fel...

PDF

+ward’ssciencewardsci.com800-962-2660 Andesite Type: Igneous; extrusive. Texture/Appearance: Generally fine-grained, aphanitic. Massive structure, often porphyritic with phenocrysts standing out in a vitreous or fine-grained groundmass. Color: Dar...

PDF

wardsci.com 800-962-2660 Scoria Type: Igneous; extrusive (volcanic). Texture/Appearance: Fine-grained to glassy; highly vesicular (>50%). Usually heavier and more crystalline than pumice. Color: Dark reddish-brown to black. Mineralogy/Chemistry: B...

PDF

wardsci.com 800-962-2660 Breccia Type: Sedimentary; clastic. Texture/Appearance: Coarse-grained, angular rock fragments cemented in a fine- to very fine-grained matrix. Clasts have sharp edges. Color: Variable. Mineralogy/Chemistry: Composition va...

PDF