apophyllite


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apophyllite

[ə′päf·ə‚līt]
(mineralogy)
A hydrous calcium potassium silicate containing fluorine and occurring as a secondary mineral with zeolites with geodes and other igneous rocks; the composition is variable but approximates KFCa4(Si2O5)4·8H2O. Also known as fish-eye stone.
References in periodicals archive ?
Typically these small cavities are lined by drusy quartz with individual quartz crystals reaching 1 cm; otherwise, only small crystals of calcite and apophyllite occur uncommonly.
The Puiva deposit, more mineralogically complex than its sister, the nearby Dodo deposit, occasionally has yielded specimens showing sharp, pale pink octahedral fluorite crystals to 1.5 cm associated with well crystallized apophyllite and axinite.
In late 2006 an extraordinary cavern complex lined with green apophyllite crystals was discovered at the bottom of a well near the small town of Bidkin, about 25 km from the old city of Aurangabad in Maharashtra Province, India.
The first spotty information about a new find of green apophyllite in India reached Europe in the fall of 2006.
An article in the September-October 2000 Mineralogical Record and an update in May-June 2007 made clear that the Millington is, as regards specimens, the newest of the many "traprock" quarries of northern New Jersey, and that its beautiful natrolite, pectolite, datolite and apophyllite specimens rank among this famous area's best.
But summer of 2007 saw a discovery in a quarry near the town of Jalna (southeast of Jalgaon) which produced flat matrix plates 4 to 15 cm across with very thin, colorless, transparent, tabular crystals of barite, uniformly around 1.5 cm, rising at varying angles from drusy colorless apophyllite: Dr.
109 Apophyllite and copper, Lake Superior [Upper Michigan], no.
The burst of white gemmy needles of mesolite seems to explode from the green apophyllite crystals below.
(2000) and later by Ottens (2001) and White (2002); detailed data confirming its presence there were given by Ottens (2003), who also described the Lonavala quarries briefly, noting the presence of green apophyllite and mesolite crystal sprays to 5 cm.
It is typically more deeply colored in the zones nearest the terminations, and is similar in its color and blocky to short-prismatic habit to the apophyllite from the Pashan Hills.
Some of the prehnite has glittering coatings of colorless, transparent apophyllite crystals with individuals to 5 mm.
Superb specimens of pectolite, natrolite, prehnite and apophyllite were found, individually and in combinations not seen before.