Botryoidal form

Crystals can also aggregate in masses that have less easily recognized crystalline forms. These masses include shapes such as botryoidal (grape-like), oolitic (pea-shaped), globular (nearly spherical), stalactitic, lamellar (platy), and dendritic (finely extended structures). Figure 105 shows botryoidal forms of both goethite and lepidolite. 

Curvilinear intratumoral calcifications may be observed in 5-10% of WT (Navoy et al. 1995). Macroscopic fatty components are rarely observed (Parvey et al. 1981), but may occur in teratoid forms (Park et al. 2003). CPDN presents as a well-limited, purely cystic mass with multiple septations (Fig. 24.3) (Agrons et al. 1995). This form has to be recognized because it is treated with primary surgery and has an excellent prognosis. Botryoid forms have been reported as WT with primarily intrapelvic development (Fig. 24.4) (Honda et al. 2000) and exceptional extension down the ureter into the bladder (Mitchell and Yeo 1997). 

Fig. 24.4. Botryoid form of Wilms tumor in a 4-year-old girl. Enhanced CT scan shows intrapelvic extension (arrow)...

Figure 8.4. Forms of polycrystalline aggregate (a) botryoidal (b) mamillary (c) spherulitic (d) oolitic (see p. 156).

Fe203.H20, is a common ore which contains about 5 per cent, of water. It occurs as an earthy deposit frequently known as red haematite and as red ochre it is also found in a compact, fibrous condition, and in botryoidal and stalactitic forms, similar to limonite, for which ore it has frequently been mistaken. It may usually be distinguished by its redder colour, its red streak, and its greater hardness. Hardness 5 to 6 density 3-56 to 4 7. When heated in a tube it splinters in a characteristic manner, which serves to distinguish it from limonite and other ores of analogous composition. 

Figure 8.5 Varnish micromorphology form ranges from botryoidal to lamellate (A and C). Two types of imagery show botryoidal varnishes from Kitt Peak, Arizona (A) the topography by secondary electrons (B) the same structures from the bottom upwards with back-scattered electrons - showing the layering structures inside each nudeation centre. (C and D) Scanning electron microscopy images of lamellate clay minerals accreting on rock varnish in Death Valley, California. (C) Individual clay platelets overlap as they cement onto the surface. (D) The clays impose a lamellate structure in cross-section, as first noticed by Potter and Rossman (1977).

Plattnerite is a lead(lV) oxide mineral with composition Pb02, named after the German metallurgist K.F. Plattner (1800-58). It occurs as black sub-metallic botryoidal masses, nodules and crusts or as prismatic crystals and forms by the oxidation of lead ore deposits in areas such as Leadhills (Scotland), Laurion (Attiki, Greece), Durango (Mexico), Tsumeb (Namibia) and Bisbee (Arizona, USA), Rutley (1988). 

Tenorite is a black copper(II) oxide mineral with composition CuO. Named after the Itahan botanist M. Tenor (1781-1861), tenorite occurs most commonly as a duU, earthy black powder or as botryoidal concretions it may also occur as scales or flakes, or in massive form. Tenorite is a secondary mineral and forms in the oxidising zone surroimding copper deposits (such as in Cornwall, England Bisbee, Arizona, USA Baha, Mexico Burra-Burra mine. South Austraha Salzburg and Tyrol, Austria Harz and Saxony, Germany), often in association with chrysocolla q.v.) and oflier secondary copper minerals. It is also known as black... 

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