| nahcolite |
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noun - (mineralogy) A saline evaporite, consisting of sodium bicarbonate, found in lake sediments in California
| | | natrolite |
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noun - (mineralogy) a fibrous zeolite mineral, being a sodium aluminosilicate
| | natron |
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noun - (mineralogy) a crystalline mixture of hydrous sodium carbonate and sodium bicarbonate
| | nepheline |
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noun
- (mineralogy) A feldspathoid mineral of silica-poor igneous, plutonic and volcanic rocks. Chemically, Nepheline is a plagioclase feldspar with insufficient silica to satisfy the chemical bonds. Because of the unfilled bonds, Nepheline weathers rapidly and can only be seen as inclusions in freshly broken rock.
- Chemical composition: Sodium potassium aluminum subsilicate, <math>(Na,K)(Al,Si)_2O_4</math>
- Physical properties:
Moh's Hardness: 5.5-6.0
Specific gravity: 2.5-2.6
Color: Colorless, white, gray, reddish, smoky; transparent to translucent
Fracture: Subconchoidal
Cleavage: Good prismatic
Habit: Hexagonal-Hexagonal pyramidal
- Fluorescence: Often orange-red in portions of crystals
| | nephrite |
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noun
- (mineralogy) A semi-precious stone, one of the two types of stone commonly referred to as jade, (the other being jadeite).
| | niccolite |
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noun - (mineralogy) a mineral, a form of nickel arsenide, NiAs?, having a metallic lustre and copper-red colour, that is a minor ore of nickel
| | nickeline |
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noun - (mineralogy) a mineral, a form of nickel arsenide, NiAs?, having a metallic lustre and copper-red colour, that is a minor ore of nickel
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