Clay used therapeutically, for example, to alleviate pain, absorb toxins, reduce swelling, or protect skin. Common healing clays are montmorillonite (in bentonite), palygorskite/sepiolite, and kaolin.
Cf., active principle, aesthetic medicine, antibacterial clay, geotherapy, medicinal clay, pelotherapy
A measure of the heat energy required to raise the temperature of a substance by 1oC. For example, the specific heat energy or capacity is the amount of heat needed to raise 1 gram of a substance by 1oC. The heat capacity is, therefore, equal to the mass of the substance times the specific heat. Thus, the molar heat capacity is the heat capacity per mole.
The energy (often heat) required to transform a given quantity of a solid to a melt without changing temperature.
Cf., heat of sublimation, heat of vaporization
The energy (often heat) required to directly transform a given quantity of a solid to a gas without changing temperature (or going through the liquid state). The heat of sublimation is the sum of the heat of fusion and heat of vaporization at the given temperature.
Cf., heat of vaporization, heat of fusion
The energy (often heat) required to transform a given quantity of a liquid into a gas or vapor without changing temperature.
Cf., heat of sublimation, heat of fusion
Hectorite is the Mg- and Li-rich trioctahedral member of the smectite group. It has the ideal chemical composition of (M+y . nH2O)(Mg3-yLiy)Si4O10(OH)2 where M is the exchangeable cation, y is the Li content, and n is variable. The M (interlayer) cation is assumed here as univalent, but it may have other valence states also. F substitution for (OH) has been documented. Stacking of natural samples is generally turbostratic. Fluorohectorite, with M = Na, K, Rb, and Cs and with y = 0.5 was synthesized by Breu et al. (2003), and the well-ordered, one-layer structure of the Cs phase was determined (space group C2/m, 1M polytype).
Cf., swinefordite
A clinopyroxene (monoclinic space group C2/c) with an end-member formula of CaFeSi2O6. Hedenbergite and diopside, CaMgSi2O6, form a continuous solid solution series. Hedenbergite primarily occurs in metamorphic rocks and skarns.
See pyroxene group for additional details.
A poorly defined material, possibly decomposed biotite.
Hemostatic wound dressings are used to control bleeding when tissue damage occurs. One active ingredient applied either directly or with gauze bandages to a wound is clay (commonly, kaolins, zeolites, and smectites), which is used to absorb fluid and to promote blood clotting.
A trioctahedral member of the true mica group. The end-member formula is KZn3AlSi3O10(OH)2. The Zn content must be greater than or equal to 1.5 for the specimen name to be valid. Reported polytypes are 1M, 2M1, and 3T. It forms in skarns of Zn deposits and occurs at Franklin Furnace, New Jersey, U.S.A.