Showing 305–320 of 483 results

Gold and Silver in Thin Section

$19.00$400.00

Petrology (from the Greek πέτρος, pétros, “rock” and λόγος, lógos, “subject matter”, see -logy) is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions, igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock.[1]

Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details.

In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through, and drawn on a log called a mud log. As the cuttings are circulated out of the borehole they are sampled, examined (typically under a 10× microscope) and tested chemically when needed.

Tephra

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Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Tephra

$19.00$400.00

Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Tephra and Sulfur

$19.00$400.00

Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Solidified Sulfur flow with Tephra

$19.00$400.00

Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Popcorn Tephra

$19.00$400.00

Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]

Tephra horizons in south-central Iceland. The thick and light coloured layer at the centre of the photo is rhyolitic tephra from Hekla.

Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.

Black Scoria from Rangitoto, New Zealand

$19.00$400.00

Rangitoto Island is a volcanic island in the Hauraki Gulf near Auckland, New Zealand. The 5.5 km wide island is an iconic and widely visible landmark of Auckland with its distinctive symmetrical shield volcano cone rising 260 metres (850 ft) high over the Hauraki Gulf.[1][2] Rangitoto is the most recent and the largest (2311 hectares)[3] of the approximately 50 volcanoes of the Auckland volcanic field.[2] It is separated from the mainland of Auckland’s North Shore by the Rangitoto Channel. Since World War II it has been linked by a causeway to the much older, non-volcanic Motutapu Island.[4]

 

Red Scoria from Rangitoto, New Zealand

$19.00$400.00

Rangitoto Island is a volcanic island in the Hauraki Gulf near Auckland, New Zealand. The 5.5 km wide island is an iconic and widely visible landmark of Auckland with its distinctive symmetrical shield volcano cone rising 260 metres (850 ft) high over the Hauraki Gulf.[1][2] Rangitoto is the most recent and the largest (2311 hectares)[3] of the approximately 50 volcanoes of the Auckland volcanic field.[2] It is separated from the mainland of Auckland’s North Shore by the Rangitoto Channel. Since World War II it has been linked by a causeway to the much older, non-volcanic Motutapu Island.[4]

 

Forensic analysis of firing pin indentation from Glock G30 on .45 cal bullet casing 50x magnification

$19.00$400.00

A bullet is a projectile expelled from the barrel of a firearm. The term is from Middle French and originated as the diminutive of the word boulle (boullet) which means “small ball.” [1] Bullets are made of a variety of materials. They are available singly as they would be used in muzzle loading and cap and ball firearms,[2] as part of a paper cartridge,[3] and much more commonly as a component of metallic cartridges.[4] Bullets are made in a large number of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, and warfare.

Forensic analysis of firing pin indentation from Glock G30 on .45 cal bullet casing 50x magnification

$19.00$400.00

A bullet is a projectile expelled from the barrel of a firearm. The term is from Middle French and originated as the diminutive of the word boulle (boullet) which means “small ball.” [1] Bullets are made of a variety of materials. They are available singly as they would be used in muzzle loading and cap and ball firearms,[2] as part of a paper cartridge,[3] and much more commonly as a component of metallic cartridges.[4] Bullets are made in a large number of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, and warfare.

Forensic analysis of firing pin indentation from Glock G30 on .45 cal bullet casing 50x magnification

$19.00$400.00

A bullet is a projectileexpelled from the barrel of a firearm. The term is from Middle French and originated as the diminutive of the word boulle (boullet) which means “small ball.” [1] Bullets are made of a variety of materials. They are available singly as they would be used in muzzle loading and cap and ball firearms,[2] as part of a paper cartridge,[3] and much more commonly as a component of metallic cartridges.[4] Bullets are made in a large number of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, and warfare.

Forensic analysis of firing pin indentation from Glock G30 on .45 cal bullet casing 50x magnification scale

$19.00$400.00

A bullet is a projectileexpelled from the barrel of a firearm. The term is from Middle French and originated as the diminutive of the word boulle (boullet) which means “small ball.” [1] Bullets are made of a variety of materials. They are available singly as they would be used in muzzle loading and cap and ball firearms,[2] as part of a paper cartridge,[3] and much more commonly as a component of metallic cartridges.[4] Bullets are made in a large number of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, and warfare.

Forensic analysis of firing pin indentation from Glock G30 on .45 cal bullet casing 50x magnification

$19.00$400.00

A bullet is a projectileexpelled from the barrel of a firearm. The term is from Middle French and originated as the diminutive of the word boulle (boullet) which means “small ball.” [1] Bullets are made of a variety of materials. They are available singly as they would be used in muzzle loading and cap and ball firearms,[2] as part of a paper cartridge,[3] and much more commonly as a component of metallic cartridges.[4] Bullets are made in a large number of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, and warfare.

Fired Bullets and Casings from Glock G21 and Glock G30 45 Caliber

$19.00$400.00

A bullet is a projectileexpelled from the barrel of a firearm. The term is from Middle French and originated as the diminutive of the word boulle (boullet) which means “small ball.” [1] Bullets are made of a variety of materials. They are available singly as they would be used in muzzle loading and cap and ball firearms,[2] as part of a paper cartridge,[3] and much more commonly as a component of metallic cartridges.[4] Bullets are made in a large number of styles and constructions depending on how they will be used. Many bullets have specialized functions, such as hunting, target shooting, training, defense, and warfare.