Rock consisting of cryptocrystalline silica alternating with microgranular quartz
For other uses, see Agate (disambiguation).
Agate
19.6 kg (43 lb) specimen of "Crazy Lace" agate from Chihuahua, Mexico next to a tennis ball; 38.2 cm (15.0 in) wide
General
Category
Chalcedony variety
Formula (repeating unit)
SiO2 (silicon dioxide)
Crystal system
Trigonal or monoclinic
Identification
Color
banded
Crystal habit
Cryptocrystalline silica
Cleavage
None
Fracture
Conchoidal, with very sharp edges
Mohs scale hardness
6.5–7
Luster
Waxy
Streak
White
Diaphaneity
Translucent
Specific gravity
2.58–2.64
Refractive index
1.530–1.540
Birefringence
up to +0.004 (B-G)
Pleochroism
Absent
Agate (/ˈæɡɪt/AG-it) is the banded variety of chalcedony,[1] which comes in a wide variety of colors. Agates are primarily formed within volcanic and metamorphic rocks. The ornamental use of agate was common in Ancient Greece, in assorted jewelry and in the seal stones of Greek warriors,[2] while bead necklaces with pierced and polished agate date back to the 3rd millennium BCE in the Indus Valley civilisation.
^Wang, Yifeng; Merino, Enrique (1990-06-01). "Self-organizational origin of agates: Banding, fiber twisting, composition, and dynamic crystallization model". Geochimica et Cosmochimica Acta. 54 (6): 1627–1638. Bibcode:1990GeCoA..54.1627W. doi:10.1016/0016-7037(90)90396-3. ISSN 0016-7037.
^"Masterpiece of Greek Art Found in the Griffin Warrior Tomb". Smithsonian. Smithsonian Institution. 7 November 2017.
Agate (/ˈæɡɪt/ AG-it) is the banded variety of chalcedony, which comes in a wide variety of colors. Agates are primarily formed within volcanic and metamorphic...
Moss agate is a semi-precious gemstone formed from silicon dioxide. It is a form of chalcedony which includes minerals of a green color embedded in the...
laboratories). "Fire Agate". www.mindat.org. Retrieved 2021-04-11. Page, Geology (2020-01-13). "Fire Agate : What is fire agate? How fire agate is formed?". Geology...
Enhydro agates are nodules, agates, or geodes with water trapped inside its cavity. Enhydros are closely related to fluid inclusions, but are composed...
The Fairburn Agate is a type of gemstone found in the agate beds of Southwestern South Dakota and Northwestern Nebraska. It is also the state gemstone...
Jeffery Stanford Agate OBE (1919 –1977) was the Managing Director of the DuPont factory at Maydown, County Londonderry, Northern Ireland. He was shot...
Agate Caune (Latvian pronunciation: [ɑːgɑːtɛ saʊnɛ] ah-GAH-teh sown-eh; born 7 August 2004) is a Latvian track and field athlete. A multiple national champion...
Mariano Agate (19 May 1939 in Mazara del Vallo – 3 April 2013 in Mazara del Vallo) was a member of the Sicilian Mafia. He was the boss of Mazara del Vallo...
James Evershed Agate (9 September 1877 – 6 June 1947) was an English diarist and theatre critic between the two world wars. He took up journalism in his...
chalcedony, a silicate mineral. Agate and onyx are both varieties of layered chalcedony that differ only in the form of the bands; agate has curved bands while...
Fire agate, a variety of chalcedony, is a semi-precious natural gemstone discovered so far only in certain areas of central and northern Mexico and the...
The Lake Superior agate is a type of agate stained by iron and found on the shores of Lake Superior. Its wide distribution and iron-rich bands of color...
Agate Pass or Agate Passage is a high-current tidal strait in Puget Sound connecting Port Madison and mainland Kitsap County in the US state of Washington...
The Agate Desert is a prairie located near White City, Oregon, 53 acres (21 ha) of which is protected as the Agate Desert Preserve. The area is not in...
The M/T Burmah Agate was an oil tanker that was involved in a nautical collision and subsequent oil spill near Galveston, Texas in November 1979. 31 crewmen...
Fordite, also known as Detroit agate or Motor City agate, is a lapidarist term for polished pieces of finely-layered paint masses from automobile factories...
The Agate Bowl (German: Achatschale) is a hardstone carving in the shape of a bowl cut out of a single piece of agate, possibly in the fourth century...
The Pylos Combat Agate is a Minoan sealstone of the Mycenaean era, likely manufactured in Late Minoan Crete. It depicts two warriors engaged in hand-to-hand...
naval trawlers of the Royal Navy were named Agate: HMT Agate (1913), sunk in 1918 by SM UC-71 HMT Agate (1933), ran aground and sank in 1941 This article...
Agate Fossil Beds National Monument is a U.S. National Monument near Harrison, Nebraska. The main features of the monument are a valley of the Niobrara...
Moss Agate Creek is a stream in the U.S. state of South Dakota. Moss Agate Creek derives its name from deposits of moss agate. List of rivers of South...
three feet. Agate House Puieblo The Agate House The Agate House Agate House window Roof entrance Where the meals were cooked Wall inside the Agate House Arizona...
Global Information