framboid

[′fram‚bȯid]

(geology)

A microscopic aggregate of pyrite grains, often occurring in spheroidal clusters.

References in periodicals archive ?

3A) as scattered euhedral cubic-octahedral crystallites, framboid aggregates or bundles (concretions) of framboidal aggregates.

Magnetic susceptibility of Middle Ordovician sedimentary rocks, Pakri Peninsula, NW Estonia/Pakri poolsaare Kesk-Ordoviitsiumi labiloike magnetiline vastuvotlikkus

In modern euxenic environments the mean framboid diameters are generally smaller (below 10 [micro]m) and have a narrower size range than for oxic and dysoxic environments (Wilkin et al.

Micromorphological evidence for mineral weathering pathways in a coastal acid sulfate soil sequence with Mediterranean-type climate, South Australia

A range of stages of development of massive crystalline aggregates is observed in the samples: individual microcrysts, framboids, framboid clusters, recrystallized megacryst overgrowths, and banded concentric zones.

Atlantic Geoscience Society

Within an individual framboid the size and habit of crystallites varied little; however, no consistent relationship between the size of framboids and individual crystals was evident.

Pyrite micromorphology in three Australian Holocene sediments

Pyrite and other sulfide minerals are often found in shales and carbonate bedrock as small (2-20 pm) framboids (Schieber, 2011; Smedley & Kinniburgh, 2002, 2005).

Elevated arsenic in private wells of Cerro Gordo County, Iowa: causes and policy changes

Pyrite is common as crystals or small nodules, framboids or replacement of macrofauna (mainly ammonites).

The hydrocarbon source rocks of the Pliensbachian (early Jurassic) in the Asturian Basin (northern Spain): their relationship with the palaeoclimatic oscillations and gamma-ray response

The presence of what appear to be degraded pyrite framboids in the deeper horizons of both apicum soils (Fig.

Soil genesis on hypersaline tidal flats (apicum ecosystem) in a tropical semi-arid estuary (Ceara, Brazil)

A lump of biological indicators as algae, framboids, disseminated pyrites, rhizolithes, rhizocretions, calcimicrobes, and filamentous bodies argue for deposition in reducing environment and extensive anoxia lead to biodegradation of organic matter.

Fossilized microbial and algal textures in post eocene lacustrine zeolite tuff sequence, G. Abu Treifiya, Cairo-Suez road, Egypt

During the late stationary growth phase or death phase, the gold NPs which were initially precipitated inside the cells were released into the bulk solution and formed suboctahedral to octahedral, subspherical to spherical aggregates resembling framboids, and ultimately millimeter-thick gold foil at longer experimental duration [148,149].

Bacteria in nanoparticle synthesis: current status and future prospects

Iron-oxide spherules are recovered from Agost section and are absent in Caravaca, where some scarce iron-oxide particulates or concretions occur but with no spherical shapes and in low quantities, mostly corresponding to altered pyrite framboids.

El limite Cretacico-Terciario en el registro marino de la Peninsula Iberica: fases de impacto meteoritico, diagenesis y efectos paleoambientales deducidos del magnetismo de rocas

Framboids are typically made of iron sulfides, but those riddling the fossils analyzed by Kaye's team--as well as Schweitzer's team in the T rex leg bone--were instead made of iron oxide.

Tissue found in dino fossil may be biofilm: new study questions analyses of T. rex remains

Crystalline inclusions in leaf tissue: (0) absent; (1) sandy; (2) druses; (3) raphides, as well as other forms; (4) framboids.