Nachcolite is a mineral of the carbonate subclass, a crystalline form of sodium bicarbonate . The name is formed by the first letters of the symbols of the chemical elements included in its composition: Na, H, C and O.
| Nakhkolit | |
|---|---|
 | |
| Formula | sodium bicarbonate NaHCO 3 |
| Physical properties | |
| Colour | colorless transparent to white; sometimes gray or brownish |
| Trait color | White |
| Shine | Glassy, resinous on cleavage planes |
| Transparency | Transparent |
| Hardness | 2,4 |
| Cleavage | Perfect in (101) and (111), average in (100) |
| Kink | Crayfish |
| Density | 2.21-2.22 g / cm³ |
| Syngonia | Monoclinic |
| Refractive index | n α = 1.377 n β = 1.503 n γ = 1.583 |
Content
Properties
Nachcolite forms prismatic crystals, often forming twins along the twin plane (101), twins of growth and sprouting often form network formations.
Nakhcolite crystals form crusts, porous masses and loose and brittle crystalline aggregates. It is soluble not only in water, but also in organic compounds (glycerin, phenolphthalein, etc.). CO 2 is released from aqueous solutions when heated . It easily melts in the flame of a soldering tube, staining the flame yellow.
Prevalence and deposits
Nachcolite is deposited in soda lakes together with other sodium carbonates - throne and thermonatrite , and also occurs in zones of secondary alteration of pegmatites of alkaline rocks.
Nachcolite is found in large quantities in the central salt strata of Lake Searls (California), forming thin strata together with other carbonate and sulfate minerals that crystallized at the last stage of salinization - bourkeite Na 4 (SO 4 ) (CO 3 ), geylussite Na 2 Ca (CO 3 ) 2 * 5H2O, nortupite Na 3 Mg (CO 3 ) 2 Cl, tenardite Na 2 SO 4 , etc.
In Russia, Nakhkolite, confined to the pegmatites of Alluive Mountain ( Kola Peninsula ), was described as large crystals of pale pink in size up to 3 cm.
Hahkolite was found as a secondary mineral in a mixture with tenardite and halite in the lava tunnels of Vesuvius and in the mud springs of Little Mogadi Lake in Kenya , it is assumed that in these cases nahkolite is formed under the influence of moisture and carbon dioxide on the throne.
See also
- Bicarbonate of soda
- Throne