Orthorhombic

2/m 2/m 2/m (D2h)

長さの異なる3軸が90度で交わる (a ≠ b ≠ c, alpha = beta = gamma = 90°)

斜方晶系は長さの異なる3軸が直角に交わります。結晶はしばしば柱状や板状の形態を示します。代表的な鉱物にはカンラン石、黄玉、霰石、重晶石、天青石、十字石などがあります。

The orthorhombic crystal system has three mutually perpendicular axes, all of different lengths (a ≠ b ≠ c, all at 90°). This creates crystals with a distinctive rectangular symmetry — like a stretched or squashed box. Approximately 22% of known mineral species crystallize in this system, making it one of the most common. The orthorhombic system includes many industrially important minerals and several prized gemstones.

Symmetry

Orthorhombic crystals have three mutually perpendicular two-fold rotation axes and/or three perpendicular mirror planes. The three unequal axes create crystals that look different from each direction but maintain perpendicular geometry. The system contains 3 crystal classes: dipyramidal (most common), pyramidal, and disphenoidal. Common crystal forms include pinacoids (pairs of parallel faces), prisms, and dipyramids. The characteristic 'tablet' or 'bladed' crystal habit of many orthorhombic minerals arises from preferential growth along one or two axes.

注目の鉱物

Olivine — the most abundant mineral in Earth's upper mantle — is orthorhombic, forming the green crystals known in gem quality as peridot. Topaz (Mohs 8) forms prismatic crystals prized as gemstones. Aragonite is the orthorhombic polymorph of CaCO₃, forming in biological systems (pearls and seashells) and around hot springs. Barite (BaSO₄) is the principal ore of barium and forms distinctive 'desert rose' crystal clusters. Sulfur crystallizes as orthorhombic bipyramids in volcanic fumaroles. Marcasite, the orthorhombic polymorph of FeS₂, forms distinctive cockscomb crystal aggregates.

鉱物 (7)

Barite

BaSO4

07 Sulfates, Chromates, Molybdates, and Tungstates

Chrysocolla

(Cu,Al)2H2Si2O5(OH)4 · nH2O

09 Silicates

Aragonite

CaCO3

05 Carbonates and Nitrates

Celestine

SrSO4

07 Sulfates, Chromates, Molybdates, and Tungstates

Olivine

(Mg,Fe)2SiO4

09 Silicates

Sulfur

S

01 Native Elements

Topaz

Al2SiO4(F,OH)2

09 Silicates

よくある質問

What is the Orthorhombic crystal system?
斜方晶系は長さの異なる3軸が直角に交わります。結晶はしばしば柱状や板状の形態を示します。代表的な鉱物にはカンラン石、黄玉、霰石、重晶石、天青石、十字石などがあります。
What minerals crystallize in the Orthorhombic system?
There are 7 minerals that crystallize in the Orthorhombic crystal system on MineralFYI.
What symmetry does the Orthorhombic system have?
The Orthorhombic crystal system has 2/m 2/m 2/m (D2h) symmetry.
What are the axes of the Orthorhombic crystal system?
The Orthorhombic system is characterized by 長さの異なる3軸が90度で交わる (a ≠ b ≠ c, alpha = beta = gamma = 90°).