Steno's Principles of Stratigraphy In 1669, Niels Stensen (1638-1686), better known then and now by his Latinized nameii Nicolau...
Growth fault
Growth faults are syndepositional or syn-sedimentary extensional faults that initiate and evolve at the margins of continental plates. T...
Contact Metamorphism
Contact Metamorphism Contact metamorphism is the name given to the changes that take place when magma is injected in the surroundi...
Volcanic Bombs
Volcanic Bombs. Fresh Volcanic Bomb photo by J.D. Griggs Volcanic bomb is a pyroclast which was semi-molten (viscous) while eject...
Hotspots the Hottest places on Earth
The places known as hotspots or hot spots in geology are volcanic regions thought to be fed by underlying mantle that is anomalously hot ...
Types of Drainage Patterns
Types of Drainage Patterns Drainage pattern a pattern created by stream erosion over time that reveals characteristics of the kind o...
Cleavage of Minerals
A cleavage plane is a plane of structural weakness along which a mineral is likely to split smoothly. Cleavage thus refers to the spli...
Volcanology
Volcanology is the study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomena. The term volcanology...
Luster of Minerals
Minerals may be categorized according to whether they are opaque or transparent . A thin section of an opaque mineral...
The Streak of Minerals
Streak plates with pyrite (left) and rhodochrosite (right) The streak (also called "powder color") of a mineral is the c...
Andradite
Locality: Dashkesan (Dashkezan) Co-Fe deposit, Dashkesan, Daşkəsən (Daskasan; Dashkyasan) District, Azerbaijan. From the Bill Lar...
Acicular Natrolit from India
Natrolite is a tectosilicate mineral species belonging to the zeolite group. Formula: Na2Al2Si3O10 · 2H2O System: Orthorhombic Colour...
Volcanic Ash the Tiny Disaster
Volcanic ash consists of fragments of pulverized rock, minerals and volcanic glass, created during volcanic eruptions, less than 2 mm (...
Fantastic Azurite
Azurite |#Geology Formula: Cu3(CO3)2(OH)2 System:Monoclinic Colour:Azure blue, blue, light ... Lustre:Vitreous Hardness:3...
Chalcedony (Agate)
Most agates occur as nodules in volcanic rocks or ancient lavas, in former cavities produced by volatiles in the original molten mass, ...
Order of Geologic Events
Applying basic geologic principles: Laws of original horizontality, superposition, and cross-cutting arelationships explain the order of...
beautiful Amethyst
Locality: Don Nicolas Mine, Villa Benegas, Mina Clavero, San Alberto Department, Córdoba, Argentina Dimensions: 10.5 cm x 6.5 cm x 5...
Principle of Original Horizontality
Principle of original horizontality The Principle of Original Horizontality was proposed by the Danish geological pioneer Nicholas ...
What is Mining?
What is Mining? Mining is the extraction of valuable minerals or other geological materials from the earth, usually from an orebody...
The Terminology of Coated Grains in Limestone
The Terminology of Coated Grains in Limestone. Pisolite by Dirk Wiersma Ooid (oolith) - a spherical to ellipsoidal grain, 0....