Mineral Information and Data:

Nd(Ti,Nb)2(O,OH)6 [CNMNC approved formula]

Named for its composition and from the Greek for "shame," in allusion to the inability of chemists, at the time of its discovery, to separate some of its constituents.

IMA status : Approved Species 1982 ()
(8th edition) :  
  (08) Multiple Oxides with Nb, Ta, and Ti
  (08.03) where A (B2O6)
  (08.03.06) Aeschynite group
(10th edition) :
  (04) Oxides and Hydroxides
  (04.D) Metal:Oxygen = 1:2 and similar
  (04.DF) With large (+- medium-sized) cations; dimers and trimers of edgesharing octahedra
Crystal system: Orthorhombic System
Point group (H-M): mmm (or 2/m 2/m 2/m) — dipyramidal
Unit cell: no data
Crystal Habit: As tabular and prismatic crystals, to several mm, and as equigranular and radiating clusters, massive
Color: Dark to pale brown, brownish black; yellowish orange to reddish orange in thin section; dark gray in reflected light.
Diaphaneity: Semitransparent
Luster: Adamantine
Hardness (Mohs): 5 - 6
Measured Density: 4.60–5.04 g/cm3
Tenacity: Brittle
Fracture: Conchoidal
Streak: Pale yellowish
Geologic Setting: In veins in slate and metamorphosed dolostone.
Mineral Association: Aegirine, riebeckite, barite, fluorite, albite, phlogopite, magnetite
Other Properties: Radioactive.
Comments: Radioactive.


8 mm long prismatic aeschynite-(Nd) crystals from small pegmatite veinlet, cross-cuting layer of zircon-feldspar-quartz hornfels
with abundant fine-grained aeschynite-(Nd).
Origin: Chungju deposit, Mt. Eorae, Joongwon-gun, Chungju (Chung Won Kum; Chung-ju), Chungcheongbukdo (Chungchong-pukto), South Korea
Photo and collection : Pavel M. Kartashov