Diaspore


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diaspore

[′dī·ə‚spȯr]
(mineralogy)
AlO(OH) A mineral composed of some bauxites occurring in white, lamellar masses; crystallizes in the orthorhombic system.

Diaspore

 

a mineral, natural aluminum hydroxide, AIOOH; contains 85 percent AI2O3 and 15 percent H2O, often with impurities of iron, chromium, manganese, and gallium oxides. Diaspores crystallizes in a rhombic system, forming lamellar, sometimes acicular, crystals. Its color is white, yellowish or pinkish white, or greenish gray. Its hardness on the mineralogical scale is 6–7; its density varies depending on the content of impurities, from 3,300 to 3,500 kg/m3. When annealed it becomes α-Al2O2 (corundum).

Diaspore is mainly concentrated in bauxites, where it appears as an ore-forming mineral together with boehmite and gibbsite. In association with corundum and chloritoids, it is found in emery deposits that are produced by the metamorphic change of bauxites. Diaspore is found in metamorphic, hydrothermic; and metasomatic deposits of the secondary quartz type.

References in periodicals archive ?
4 percent of Al2O3 and Altogether Gibbsite is recovered with a purity of 90% [3] In China diaspore bauxite is recognized with high volume of Al2O3 and SiO2 and relatively low Al2O3 to SiO2 (usually the amount is m (Al2O3)/m (SiO2) = A/S (5-6)) and this ratio of Gibbsite bauxite and Boehmite bauxite is compared with other countries.
51 [4]It was suggested to conduct the separation by using diaspore floatation method of kaolinite, illite and pyrophyllite, with a cationic collectors with a pH between 2 and 7.
The experimental design was completely randomized, using five treatments and four replicates of 30 diaspores of Echinochloa crus-galli and Ipomoea grandifolia.
To evaluate the influence of the osmotic potential of the extracts, germination bioassays with diaspores of Echinochloa crus-galli and Ipomoea grandifolia using polyethylene glycol 6000 (PEG 6000) solutions at -0.
Each parcel consisted of 50 diaspores for germination and 10 for root and hypocotyl/coleoptile growth.
The bioassays of the initial growth of aerial (AP) and root (RP) weed parts were conducted using four replicas of ten seeds or diaspores pre-germinated in distilled water (2-4 mm of radicle) per plastic box.
The barnyard grass diaspores germinated synchronously (approximately 4 days), and therefore, they showed reduced germination informational entropy despite the increase in germination average time.
However, it is equally conceivable that the development of these adaptations is also a consequence of the ability of the Tillandsioideae to reach the canopy with their diaspores.
Most genera of nuts appear to have evolved from ancestors with wind-dispersed diaspores.
Spores of many fungi, lichens, and mosses, asexual diaspores of lichens (soredia and isidia) and thallus fragments of cyanobacteria are 1-50 [[micro]meter] in diameter and can be dispersed as components of aerosols (Akers et al.
Simultaneously, litter packs also work as floaters for diaspores during dispersal.