Nile Silt Fabrics

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Nile Silt Fabrics, as classified by the Vienna System, are those based on manufacture from a Nile silt ceramic paste.

• Mineral particle inclusions, whether sand or limestone, are divided into three broad categories:
  • fine (60-250 µ)
  • medium (250-500 µ)
  • coarse (> 500 µ).
• Straw inclusions are similarly divided, by length of particle, into three broad categories:
  • fine (< 2 mm)
  • medium (2-5 mm)
  • coarse > 5 mm)

The Vienna System: Nile Silt Fabrics

-	Nile A	Nile B1	Nile B2	Nile C	Nile D	Nile E
Texture / Composition	Homogeneous fine clay with significant amount of silt. Abundant inclusion of fine sand, with some medium sand present. Occasional grains of coarse sand. Mica particles common.	Clay texture silty and fine, though less so than Nile A. Abundant inclusion of fine sand, with scattered particles of medium to coarse sand. Mica particles common.	Resembles Nile B1 closely, but with larger and more frequent inclusions of all types. Abundant inclusion of fine sand; medium sand common. Some rounded sand grains may be present, as well as scattered limestone particles (some with indications of decomposition: reaction rims).	Fairly silty clay, with sub-angular to rounded sand grains ranging in size from fine to coarse and from scarce to common in frequency. Limestone particles of medium size may occur thinly throughout the paste, but not so conspicuously as per Nile D.	Reflects full range of fabrics in Nile A-C: a fabric group rather than a discreet fabric.	Reflects range of fabrics in Nile B or Nile C; distinguished by conspicuous to abundant rounded sand grains of fine, medium and coarse size.
Inclusions	Characterised by lack of plant remains, except for a very few fine straw particles probably introduced inadvertently.	Scattered fine to medium straw particles present as surface impressions or silica skeletons of plant structure.	Conspicuous plant remains: fine to medium straw, with occasional scattered coarse straw particles.	Widest range of inclusions amongst Nile Silt fabrics. Apart from scattered limestone particles, other mineral inclusions may include mica, grog and rock particles of medium to coarse size. Abundant quantity of medium to coarse straw remains (> 5 mm), visible both on the surface and in section as either carbonised particles, as white / light grey silica skeletons of cellular structure or empty impressions.	Conspicuous limestone inclusions (whether soil admixture in the paste or added temper).	Apart from dominant sand particles, other mineral inclusions include angular and sub-angular sand grains of fine to coarse particle size. Mica particles are common.
Fracture Colour	Brown to greyish-brown without strongly defined zoning (indicates well-controlled firing over long duration).	Frequently uniform brown to reddish-brown. Black/grey or black/red zoning can occur: black cores or narrow red cores with violet outer zones.	Considerable variability: normally brown, but may show black core	Grey-brown to reddish-brown normally; black cores may appear in thick-walled vessels (up to 2 cm thickness)	Outer zones of red and even violet colour, with a black core. Surface and fracture occasionally reveal uniform red colour.	Brown to black (reflects low firing temperature)
Porosity	Moderate to dense	Moderate to dense	Loose and open to moderate	Loose and open; frequent indications of poor mixing of paste and / or uneven firing	Variable porosity: often very hard	Loose and open, porous
Hardness	Medium	Soft to medium	Medium to hard	Soft to medium	Usually very hard and highly-fired	Soft, crumbly; some soft to medium
Transverse Strength	Medium to great	Low to medium	Medium to great	Low to medium	Great, moderate to great (partly due to high firing temperature)	Low to medium
Range	Common throughout the Predynastic —from the Badarian Period onwards—to the Early Dynastic Period. Afterwards rare, but occurs in the MK to SIP in the Eastern Delta (Tell el-Dabʿa)	Common from OK to start of 18th Dynasty.	Common in all regions and at all periods; inherently greater variability than Nile B1 in aspects firing-related (colour, porosity, hardness).	Occurs in all regions and at all periods, with wide variability.	no observation	Middle Kingdom to New Kingdom periods only. Restricted geographical limits: found in the Eastern Delta and the Memphite region as far south as the Faiyum.
Application	Employed within a lareg variety of vessel forms, including flasks and cone-shaped vessels.	Employed within hemispherical bowls, the characteristic and widespread drinking cup of the MK; especially characteristic of fine wares in the Delta and the Faiyum-Memphis regions in that period.	no observation	Frequently employed for large, heavy thick-walled containers: examples include bread trays and large storage jars.	no observation	Employed within a wide range of vessels in the Eastern Delta region (Tell el-Dabʿa; Qantir = 95% of Nile clay vessels). Use more specialized in the Memphite region, most frequently employed for bread moulds and cooking vessels.
Additional Observations	Fine texture possibly derives from process of natural levigation, perhaps in pools of water residual from the annual Nile inundation. The even gradation in size between the groundmass and fine sand inclusions suggests the sand is a natural component of the paste and not added temper. Firing temperature 700℃-750℃.	Sherd appearance suggests a well-mixed paste and steady firing conditions over a long duration. Nile B1 vessels characteristically have very thin walls, with considerable bearing on fabric / sherd colour, porosity and hardness.	Occasional occurrence of mussel shell fragments and limestone concretions, revealing derivation from Delta geziras (sandbanks) in Tell el-Dabʿa examples. Some Karnak samples of late 18th Dynasty date contain grog, possibly accidental inclusions.	Firing temperature relatively low at 500℃-800℃; surface frequently reveals smoky patches from uneven firing conditions.	High firing temperature. Indications of incipient vitrification and reaction rims from burnt out limestone inclusions may occur.	no observation
Examples		none	none	none	none	none

Bibliography

• Bourriau, Janine [1981], Umm el-Gaʿab - Pottery from the Nile Valley before the Arab Conquest, [catalogue by Janine Bourriau; exhibition organised by the Fitzwilliam Museum, Cambridge, 6 October to 11 December 1981], Cambridge: Cambridge University Press, 1981. ISBN 0521240654 (cloth) ISBN 0521284155 (paper)

• Nordtsröm, Hans-Åke and Bourriau, Janine [1993], "4. The Vienna System", Chapter 4 in Ceramic Technology: Clays and Fabrics, Fascicle 2 in Arnold, Dorothea and Bourriau, Janine (eds) [1993], An Introduction to Ancient Egyptian Pottery, [Deutsches Archäologisches Institut Abteilung Kairo Sondershrift 17], Mainz am Rhein: Philipp von Zabern, 1993, pp.168-182, pls. I-VII. ISBN 3805306237.
  • [Nile Silt fabrics are described pp.170-175, pls.I-III].