Fundamental Minerals

Sialic Minerals

Feldspar

Feldspathoid

Quartz

Femic Minerals

Accessory Minerals

Very Rare Minerals

Secondary Minerals

Texture

Alteration Products

Glass and related Texture

Volcanic Rocks

Komatiites

Lamprophyres

Limburgite

Limburgite: "A basic volcanic rock containing phenocrysts of pyroxene, olivine and opaques in a glassy groundmass containing the same minerals. No feldspars are present. May be used as synonym for a hyalo-nepheline basanite". (Le Maitre, 2005).

The Term "Limburgite" derives from the type locality at Limberg or Limburg (Fig.1), close to Sasbach am Kaiserstuhl in Baden-Württemberg. Limburgite was first defined in 1872 by Harry Rosenbusch a German petrographer. This rock name is nowadays seldom used and it is one out of more than thousand rock names that were given to all kinds of igneous rocks during 19th and 20th century. Such a proliferation of names is understandable because at the time there were no uniformly accepted classification principles to use and everyone would be pleased to name a new rock type.

Fig.1. a) geological map of the Kaiserstuhl volcanic complex after Wimmenauer (1966). b) Schematic profile of the Upper Rhine-graben. Modified from Walter, B. F et., al (2016).

Limburgite consists essentially of olivine and augite with a brown, glassy groundmass in which a second generation of small augite crystals is commonly found. The principal accessory minerals are titaniferous iron oxides and apatite; in some limburgites, hornblende and biotite are found as large scattered crystals, in others orthoclase or anorthoclase. In others there are large crystals of anorthoclase. Typical limburgite contains lots of vesicules that are partly filled with secondary minerals (amygdaloidal texture). Since the early days of its geological and mineralogical exploration, the Kaiserstuhl volcanic complex is very famous for its wealth in zeolites.

Limberg quarry
The Limberg (Fig. 2). belongs to the Limberg-Lützelberg Complex, a parasitic volcano in the NW corner of the Kaiserstuhl volcanic complex. It is composed of a succession of lavas (named l1-l5) and agglomerates of tephrite, nephelinite and basanite ("limburgite") and intercalated tuffs (t1-t4) of tephritic and phonolitic affiliation, which probably erupted from a strombolian-type vent on the southern Limberg.
The mantle-xenolith bearing olivine nephelinite flow forming the Lutzelberg reaches a length of 1.4 km and a maximum thickness of 50 m. Synvolcanic extensional deformation formed the 150 m wide, NW-SE striking Limberg Graben, which is filled with Burdigalian marls and sandstones of the Limberg Formation. These sediments are overlain by the younger tuff t3 (16.2 +/- 0.2 Ma) and the lava flow units l3 and l4.

Fig.2: Limberg Geological map

Limburgite quarry, Sasbach. From La lithothèque

Sample of Limburgite. From Geologische Streifzüge

Sample of Limburgite with vesicles filled by philipsite. From Mineral forum.

Sample of Limburgite with vesicles filled by philipsite. From From Geologische Streifzüge

Bibliography

• Exkursion zur Vulkanologie und Tektonik des Oberrheingrabens. Gerhard Brügmann und Dieter Mertz
• Lixian-xun W; Michael A.W. Marsk; Thomas W.; Annette Von der Handt; Jorg. K.; Holger T.; Gregor M. (2004): Apatites from the Kaiserstuhl Volcanic Complex, Germany: new constraints on the relationship between carbonatite and associated silicate rocks. Eur. J. Mineral. 2014, 26, 397–414
• Ulianov. A; Muntener. O; Ulmer. P; Pettke.T (2007): Entrained Macrocryst Minerals as a Key to the Source Region of Olivine Nephelinites: Humberg, Kaiserstuhl, Germany. J. Of Petrology, vol.48, N.6. 1079-1118 (2007)

Photo
Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. PPL image, Field of view = 2,5 cm.	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, Field of view = 2,5 cm.	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)
Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 1x (Field of view = 9mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. PPL image, 1x (Field of view = 9mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 1x (Field of view = 9mm)
Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. PPL image, 1x (Field of view = 9mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 1x (Field of view = 9mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 1x (Field of view = 9mm)
Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Augite crystals within a glassy groundmass. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Altered olivine crystals (by iddingsite). Limberg, Kaiserstuhl, Germania. PPL image, 10x (Field of view = 2mm)
Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)
Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)
Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)	Augite crystals within a glassy groundmass and vesicles with phillipsite crystals. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)
Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Phillipsitee crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)
Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)
Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. PPL image, 2x (Field of view = 7mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 2x (Field of view = 7mm)
Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 10x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 10x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 10x (Field of view = 2mm)
Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 10x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. PPL image, 10x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 10x (Field of view = 2mm)
Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 10x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. PPL image, 20x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 20x (Field of view = 2mm)
Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 20x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 20x (Field of view = 2mm)	Phillipsite crystals filling a volcanic vesicle. Limberg, Kaiserstuhl, Germany. XPL image, 20x (Field of view = 2mm)