Table of Contents
What is the luster of a metamorphic rock?
Retained in metamorphism. Description: Nonmetallic luster. Twinning. Wiese Page 3 Rock type: Mineral in metamorphic rocks Formation Environment: Low grade metamorphism of mudstones and basalts.
How do you describe the luster of a rock?
Lustre (British English) or luster (American English; see spelling differences) is the way light interacts with the surface of a crystal, rock, or mineral. A range of terms are used to describe lustre, such as earthy, metallic, greasy, and silky.
Are igneous rocks shiny?
Igneous rocks are formed when magma (molten rock deep within the earth) cools and hardens. When lava cools very quickly, no crystals form and the rock looks shiny and glasslike. Sometimes gas bubbles are trapped in the rock during the cooling process, leaving tiny holes and spaces in the rock.
What are types of luster?
They are: metallic, submetallic, nonmetallic, vitreous, dull, greasy, pearly, resinous, silky, waxy, and adamantine. These adjectives convey – in a single word – a property that can be important in the identification of a mineral. The luster of a material can also determine how it will be used in industry.
What is the luster of limestone rock?
Its luster ranges from vitreous to dull; many crystals, especially the colourless ones, are vitreous, whereas granular masses, especially those that are fine-grained, tend to be dull.
What are the 4 textures of igneous rocks?
Igneous Rock Textures
- COARSE GRAINED TEXTURE (PHANERITIC), mineral grains easily visible (grains several mm in size or larger)
- B) FINE GRAINED TEXTURE (APHANITIC), mineral grains smaller than 1mm (need hand lens or microscope to see minerals)
- C) PORPHYRITIC TEXTURE (MIXED FINE AND COARSE)
What are the 4 igneous textures?
Igneous textures are used by geologists in determining the mode of origin of igneous rocks and are used in rock classification. There are six main types of textures; phaneritic, aphanitic, porphyritic, glassy, pyroclastic and pegmatitic.