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| Andalusite (Al2O(SiO4)) Basic information |
| Andalusite (Al2O(SiO4)) Chemical Properties |
| Andalusite (Al2O(SiO4)) Usage And Synthesis |
Chemical Properties | gray, greenish, reddish, or bluish; hardness 7–7.5; used in dental cements and the glass industry, in enamels, ceramics, and as a paint filler [MER06] [HAW93] | Physical properties | Habit: acicular, blocky, prismatic, euhedral crystals. Color: usually pink, white, rose, dark
green, gray, brown, red, or green or with clouded inclusions. Luster: vitreous (i.e., glassy). Diaphaneity: transparent to translucent. Cleavage: (110) distinct, (100) indistinct, (010)
poor. Fracture: uneven, splintery, brittle. Streak: white. Chemical: insoluble in strong
mineral acids but attacked by molten alkali-metal hydroxides (e.g., NaOH) and carbonates
(e.g., Na2CO3). Heated in Co(NO3
)2 give the Thénard blue color. Non fusible but transforms
to sillimanite on heating. Other properties: Unfusible but when heated above 1200°C
transforms to a mixture of silica and mullite (Al6Si2O13). Dielectric constant of 8.28.
Diamagnetic with a specific magnetic susceptibility of –10–10 m3.kg–1. Occurrence: metamorphosed peri-aluminous sedimetary rocks. | Production Methods | It was estimated that in 1987, 90% of the kyanite produced in
the United States was used in refractories, 55% of this for
smelting and processing iron, 20% for smelting and processing
nonferrous metals, and15% for refractories in glassmaking
and ceramics. |
| Andalusite (Al2O(SiO4)) Preparation Products And Raw materials |
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