Monoclinic

2/m (C2h)

길이가 다른 세 축으로, 두 축은 90도로 교차하고 한 축은 기울어짐 (a ≠ b ≠ c, alpha = gamma = 90°, beta ≠ 90°)

단사정계는 길이가 다른 세 축을 가지며, 하나의 축이 나머지 두 축에 대해 비스듬히 기울어져 있습니다. 광물 중 가장 흔한 결정계로, 결정은 흔히 기둥 또는 판상 습성을 나타냅니다. 정장석, 단사휘석, 석고, 녹렴석, 다수의 각섬석이 이에 속합니다.

The monoclinic crystal system is the most common crystal system for minerals, hosting approximately 32% of all known species. Its three unequal axes include one oblique angle (a ≠ b ≠ c, α = γ = 90°, β ≠ 90°), creating a characteristic 'leaning' appearance. The slight departure from perpendicularity gives monoclinic crystals their distinctive tilted geometry, readily visible in minerals like orthoclase feldspar and gypsum.

Symmetry

Monoclinic symmetry requires one two-fold rotation axis (the b-axis) and/or one mirror plane perpendicular to it. The oblique β angle (typically 90-120°) breaks the rectangular symmetry of the orthorhombic system. The system contains 3 crystal classes: prismatic (most common, with 2/m symmetry), sphenoidal, and domatic. The characteristic 'clinopinacoid' face ({010}) is perpendicular to the unique b-axis. Twinning is extremely common in monoclinic minerals, with contact twins (like gypsum's 'swallowtail' twins) and penetration twins (like orthoclase's Carlsbad twins) being classic examples.

주요 광물

The feldspars — the most abundant mineral group in Earth's crust — include monoclinic members like orthoclase and sanidine (potassium feldspars). Gypsum (CaSO₄·2H₂O) forms transparent 'selenite' crystals up to 12 meters long in Mexico's Cave of the Crystals. Augite and hornblende, the most common pyroxene and amphibole respectively, are monoclinic and abundant in igneous and metamorphic rocks. Epidote forms distinctive pistachio-green prismatic crystals. Malachite's rich green color and banded patterns make it one of the most recognizable monoclinic minerals, prized for ornamental use since ancient Egypt.

광물 (10)

Biotite

K(Mg,Fe)3(AlSi3O10)(OH)2

09 Silicates

Azurite

Cu3(CO3)2(OH)2

05 Carbonates and Nitrates

Muscovite

KAl2(AlSi3O10)(OH)2

09 Silicates

Wolframite

(Fe,Mn)WO4

07 Sulfates, Chromates, Molybdates, and Tungstates

Staurolite

Fe2Al9Si4O23(OH)

09 Silicates

Talc

Mg3Si4O10(OH)2

09 Silicates

Feldspar (Orthoclase)

KAlSi3O8

09 Silicates

Gypsum

CaSO4 · 2H2O

07 Sulfates, Chromates, Molybdates, and Tungstates

Malachite

Cu2(CO3)(OH)2

05 Carbonates and Nitrates

Epidote

Ca2(Al,Fe)3(SiO4)(Si2O7)O(OH)

09 Silicates

자주 묻는 질문

What is the Monoclinic crystal system?
단사정계는 길이가 다른 세 축을 가지며, 하나의 축이 나머지 두 축에 대해 비스듬히 기울어져 있습니다. 광물 중 가장 흔한 결정계로, 결정은 흔히 기둥 또는 판상 습성을 나타냅니다. 정장석, 단사휘석, 석고, 녹렴석, 다수의 각섬석이 이에 속합니다.
What minerals crystallize in the Monoclinic system?
There are 10 minerals that crystallize in the Monoclinic crystal system on MineralFYI.
What symmetry does the Monoclinic system have?
The Monoclinic crystal system has 2/m (C2h) symmetry.
What are the axes of the Monoclinic crystal system?
The Monoclinic system is characterized by 길이가 다른 세 축으로, 두 축은 90도로 교차하고 한 축은 기울어짐 (a ≠ b ≠ c, alpha = gamma = 90°, beta ≠ 90°).