Search results
Results from the WOW.Com Content Network
Quartzite is a very hard rock composed predominantly of an interlocking mosaic of quartz crystals. The grainy, sandpaper-like surface is glassy in appearance. Minor amounts of former cementing materials, iron oxide, silica, carbonate and clay, often migrate during recrystallization, causing streaks and lenses to form within the quartzite. [1 ...
Quartz. Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2. Quartz is, therefore, classified structurally as a framework silicate mineral ...
A quartz crystal microbalance (QCM) (also known as quartz microbalance (QMB), sometimes also as quartz crystal nanobalance (QCN)) measures a mass variation per unit area by measuring the change in frequency of a quartz crystal resonator. The resonance is disturbed by the addition or removal of a small mass due to oxide growth/decay or film ...
Aventurine. Aventurine is used for a number of applications, including landscape stone, building stone, aquaria, monuments, and jewelry. Aventurine is a form of quartzite, characterised by its translucency and the presence of platy mineral inclusions that give it a shimmering or glistening effect termed aventurescence.
The room-temperature form of quartz, α-quartz, undergoes a reversible change in crystal structure at 573 °C to form β-quartz. This phenomenon is called an inversion, and for the α to β quartz inversion is accompanied by a linear expansion of 0.45%. This inversion can lead to cracking of ceramic ware if cooling occurs too quickly through ...
Specimen from California, US; size: 5.9 cm × 3.8 cm × 3.8 cm (2.3 in × 1.5 in × 1.5 in). Cristobalite (/ krɪˈstoʊbəˌlaɪt /) is a mineral polymorph of silica that is formed at very high temperatures. It has the same chemical formula as quartz, Si O 2, but a distinct crystal structure. Both quartz and cristobalite are polymorphs with ...
Herkimer diamonds are double-terminated quartz crystals discovered within exposed outcrops of dolomite in and around Herkimer County, New York, and the Mohawk River Valley in the US. [1][2] They are not diamonds; the "diamond" in their name is due to both their clarity and well formed faces. Because the first discovery sites were in the village ...
Electrochemical quartz crystal microbalance (EQCM) is the combination of electrochemistry and quartz crystal microbalance, which was generated in the eighties. [1][2][3] Typically, an EQCM device contains an electrochemical cells part and a QCM part. [4] Two electrodes on both sides of the quartz crystal serve two purposes. [4]