Mosaics In Situ Project

ILLUSTRATEDGLOSSARY

Definitions of terms used for the graphic documentation of in situ floor mosaics

Developed by the Getty Conservation Institute and the Israel Antiquities Authority

December 2003

2www.getty.edu/conservation/

INTRODUCTION

The present glossary is the result of collaborative work between the Getty

Conservation Institute and the Israel Antiquities Authority as part of the research

component of the Mosaics In Situ Project and was subsequently revised during the

course of technician training in Tunisia in collaboration with the Institut National du

Patrimoine.

The objective of this glossary is to establish a common and unambiguous vocabulary

for the recording of the conditions of and interventions on in situ floor mosaics. The

terms in the glossary are divided into CURRENT CONDITION, defined in written form

and illustrated, and CURRENT INTERVENTION, only defined in written form.

This mosaic glossary is by no means comprehensive and must be considered a "base"

document that could be adapted and added to as necessary. According to the

specific requirements of the conservation program, the terms and definitions provided

can be utilized as they are or can be tailored to the work at hand.

- Specific terms can be subdivided when more detail is required. For example, fills

can be subdivided in modern fills and ancient repairs.

- Terms can be grouped either when conditions always occur together or when

less detail is required. For example, deteriorated tesserae can be used to

describe different conditions such as exfoliated, fractured, and pitted tesserae.

Another example is deteriorated border, which can comprise both detached

tesserae and the deteriorated preparatory layer located at the edge of the

tesselatum.

- Alternative terms can be used. For example loss can be used instead of lacuna.

- New terms can be created to describe a condition specific to a mosaic and not

included in this glossary.

The glossary has been developed to achieve objective recording. Therefore the

written descriptions are formulated as much as possible with no reference to the

cause of damage, but only to the visual evidence observed on site.

Some of the written definitions have been borrowed and/or adapted as necessary

from existing glossaries for the conservation of plaster, stone, wall paintings, and

mosaics.

3www.getty.edu/conservation/

MOSAIC STRATIGRAPHY

The following stratigraphy is adapted from ancient literary sources.It is to be used only as a general reference in this document. Inpractice, all mosaics do not necessarily display this stratigraphy.

A mosaic can be built on natural ground made of soil or rock, oron top of a previous pavement. The mosaic itself is composed of avariety of foundation or preparatory layers and a layer of tesserae.

1 - Statumen - First preparatory layer which is made of largestones laid on the ground, previously leveled and rammed. Thislayer only exists if the mosaic has been constructed on a naturalsoil.

2 - Rudus - Second preparatory layer which is spread over thestatumen. This layer is made of a lime mortar with largeaggregates.

3 - Nucleus - Third preparatory layer which is spread over therudus in a thinner layer. The nucleus is made of a mortar with fineaggregates.

4 - Bedding layer - Fourth preparatory layer of mortar which isvery rich in lime, and thinly applied in small sections over thenucleus. Tesserae are inserted in this layer before the mortar sets.

5 - Tessellatum - Layer which consitutes the mosaic surface and iscomposed of tesserae and mortar filling the interstices betweenthem.

4www.getty.edu/conservation/

LIST OF THE TERMS USED

1. CURRENT CONDITON

1.1. Previous InterventionsEdging repairFillFill between tesseraeTreated surfaceRe-laid areaJoints between re-laid sectionsMetallic elements

1.2. Structural ConditionsCrackLacunaCavityDetached tesseraeDeteriorated preparatory layersDetachment between mosaic layersDepressionRise / BulgePlant intrusionDeteriorated repair mortar

1.3. Surface ConditionsDeteriorated tesserae

Disaggregated tesseraeEroded tesseraeExfoliated tesseraeFractured tesseraePitted tesserae

DepositEfflorescenceIncrustationMicrobiological organismsColor alteration

2. CURRENT INTERVENTION (in alphabetical order)

CleaningConsolidation of preparatory layersConsolidation of tesseraeEdging repairFacingGroutingFillingFilling between tesseraeRemoval of previous repairsResetting of tesseraeTreatment of higher plantsTreatment of microbiological organisms

5www.getty.edu/conservation/

EDGING REPAIR

Mortar reinforcing a mosaicborder or edge.

Within a single mosaic, edgingrepairs can be classifiedaccording to their color, surfacetexture and material utilized.

FILL

Area where the originaltessellatum is missing and theresulting lacuna has been filled,either in antiquity or in themodern period.

Within a single mosaic, fills canbe classified according to theirdate, color, surface texture andmaterial utilized; e.g. mortaralone or mortar with variousmaterials bedded in it, such astesserae, larger stone orceramic fragments.

Fills using tesserae orattempting to indicate thedesign with other materialsmay be termed reintegration.

FILL BETWEENTESSERAE

Area where the original mortarin the interstices between thetesserae has been replaced.

CURRENT CONDITION - Previous Interventions

6www.getty.edu/conservation/

JOINTS BETWEENRE-LAID SECTIONS

Spaces between the sections ofa mosaic that has been cut,detached, and re-laid in situ.

The cuts may or may notfollow the design of themosaic. Joints may have beenleft empty or filled with amaterial (mortar, tesserae, etc.)to restore the continuity of themosaic surface.

CURRENT CONDITION - Previous Interventions

METALLIC ELEMENTS

Structural reinforcementsbelonging to the new supportof a re-laid mosaic.

RE-LAID AREA

Part of the tessellatum whichhas been detached from itspreparatory layers, in sectionsor in one piece, and re-laid insitu on a new support.

TREATED SURFACE

Area of the tessellatum wherematerial has been appliedintentionally to consolidate,protect or enhance the color ofthe mosaic surface, such aswax, chemical consolidant.

7www.getty.edu/conservation/

CRACK

Linear breaks visible at thesurface of the mosaic, whichmay also penetrate into itslower layers.

The word fracture is alsocommonly used to describethis condition.

LACUNA

Area of the mosaic where thetessellatum is missing.

Within a single mosaic, lacunaecan be classified according totheir depth; for example lacunaof tessellatum, bedding layer ornucleus.

The word loss is also commonlyused to describe this condition.

CAVITY

Area of sub-surface loss.

Cavities can be due to watererosion or animals, includinginsects, burrowing.

CURRENT CONDITION - Structural Conditions

8www.getty.edu/conservation/

DETERIORATEDPREPARATORYLAYERS

Loss of physical integrity withinone or more layers of mortarsupporting the tessellatum asmanifested by cracks,disaggregation, erosion, etc.

DETACHMENTBETWEEN MOSAICLAYERS

Lack of adhesion between twolayers of the mosaic.

A detachment is not alwaysvisible and can be detected bythe corresponding hollowsound produced when thesurface of the mosaic is tapped. Detachment with void Detachment without void

DETACHED TESSERAE

Tesserae which are still in theiroriginal location but have lostadhesion to the bedding layerand, as a result, move whenlightly touched.

CURRENT CONDITION - Structural Conditions

9www.getty.edu/conservation/

DEPRESSION

Downward deformation of themosaic below its originalsurface level.

RISE / BULGE

Upward deformation of themosaic above its originalsurface level.

CURRENT CONDITION - Structural Conditions

10www.getty.edu/conservation/

CURRENT CONDITION - Structural Conditions

PLANT INTRUSION

Vegetation, such as weeds,grasses, bushes and trees, andtheir associated roots which arepresent under, within or on topof the mosaic.

DETERIORATED REPAIRMORTAR

Loss of physical integrity ofedging repairs or mortar fills asmanifested by cracks,disaggregation, erosion, etc.

11www.getty.edu/conservation/

DETERIORATEDTESSERAE

Tesserae which have suffered aloss of material or of physicalintegrity.

Deteriorated tesserae can bedescribed more precisely asDisaggregated, Eroded,Exfoliated, Fractured, Pitted,etc.

DISAGGREGATEDTESSERAE

Tesserae displaying loss ofcohesion of their surfaces,which have disintegrated intopowder or small grains.

ERODED TESSERAE

Tesserae displaying a worn orabraded surface.

SUBCATEGORIES OF DETERIORATED TESSERAE (in alphabetical order)

CURRENT CONDITION - Surface Conditions

12www.getty.edu/conservation/

CURRENT CONDITION - Surface Conditions

FRACTUREDTESSERAE

Tesserae diplaying linear breaksor network of breaks throughtheir matrix.

PITTED TESSERAE

Tesserae displaying numeroussmall, rounded cavities on theirsurface.

EXFOLIATEDTESSERAE

Tesseare displaying detachmentor loss of layers, parallel orperpendicular to the mosaicsurface.

13www.getty.edu/conservation/

INCRUSTATION

Mineral crust formationadhering to the mosaic surface,often hard and compact, andof variable thickness andextent.

MICROBIOLOGICALORGANISMS

Small organisms of variouscolors and forms, living ordead, such as fungi, algae,lichens, mosses, or bacteria,which adhere to the mosaicsurface.

DEPOSIT

Accumulation of extraneousmaterial of various types, suchas soil, sand, animal droppingsand vegetal materials, ofvariable thickness, and pooradhesion to the mosaicsurface.

EFFLORESCENCE

Formation at the mosaicsurface of a loosely adheringsubstance, generally white andcrystalline, powder-like orwhisker-like in appearance.

CURRENT CONDITION - Surface Conditions

14www.getty.edu/conservation/

COLOR ALTERATION

Alteration of the mosaic surfacecharacterized by a localizedchange in color.

Color alterations may betermed more precisely metallicstains, fire damage, graffiti, etc.

CURRENT CONDITION - Surface Conditions

15www.getty.edu/conservation/

CURRENT INTERVENTION

CLEANING

Removal of extraneous substancesfrom the mosaic surface, with orwithout water, and with tools suchas sponges, brushes, scalpels,wooden tools, dental instruments,etc.

CONSOLIDATION OFPREPARATORY LAYERS

Application of a material (natural orsynthetic product) to restorecohesion to preparatory layers.

CONSOLIDATION OFTESSERAE

Application of material (natural orsynthetic product) to restorecohesion to individual tesserae.

EDGING REPAIR

Application of a mortar along theedges of a mosaic.

FACING

Application of gauze or similarmaterial on the mosaic surface withan adhesive for its temporaryprotection during treatment.

GROUTING

Introduction of a fluid binder-aggregate mixture into a voidbetween preparatory layers.

FILLING

Application of a mortar and/or othermaterials in an area of loss of themosaic surface.

FILLING BETWEENTESSERAE

Application of a mortar in theinterstices between the tesserae.

REMOVAL OF PREVIOUSREPAIRS

Elimination of previousinterventions, such as edging repairsand fills.

RESETTING OF TESSERAE

Replacement of detached tesserae intheir original position using anadhesive mortar.

TREATMENT OF HIGHERPLANTS

Reduction or removal of trees andplants by mechanical or chemicalmeans.

TREATMENT OF MICRO-BIOLOGICAL ORGANISMS

Reduction or removal ofmicrobiological organisms bymechanical or chemical means.

16www.getty.edu/conservation/

TEXTText compiled by Elsa Bourguignon, Jacques Neguer, Francesca Piqué, Thomas Roby; reviewed by Livia Alberti, Evelyne Chantriaux, Martha Demas, Jerry Podany,John Stewart, Jeanne-Marie Teutonico.

IMAGESInformation is given in the following order: Site, country. Mosaic name (if available). Date. Photographer name © Copyright.

Cover Horvat Minnim, Israel. September 1998. Frank Long © J. Paul Getty Trust

Page 3Stratigraphy drawing by Haim Kapschitz, modified by Elsa Bourguignon © J. Paul Getty Trust

Page 5Edging repair

Left photo: Paphos, Cyprus. January 1999. Francesca Piqué © J. Paul Getty TrustRight photo: Masada, Israel. West palace mosaic. August 1997. Francesca Piqué © J. Paul Getty Trust

FillTop left photo: Bardo Museum, Tunis, Tunisia. May 1997. Gaetano Palumbo © J. Paul Getty TrustTop right photo: Utica, Tunisia. Maison de la Cascade, room XXIa. November 2001. Elsa Bourguignon © J. Paul Getty TrustBottom left photo: Caesarea, Israel. Francesca Piqué © J. P. Getty TrustBottom right photo: Vatican. Reintegrated mosaic in Vatican Museum. November 2003. Francesca Piqué © J. Paul Getty Trust

Fill between tesseraeLeft photo: Thuburbo Majus, Tunisia. Maison de Neptune, room XIV. May 2002. Elsa Bourguignon © J. Paul Getty TrustRight photo: Caesarea, Israel. May 2000. Gaetano Palumbo © J. Paul Getty TrustBottom drawing: Drawing by Haim Kapschitz, modified by Elsa Bourguignon © J. Paul Getty Trust

Page 6Treated Surface

Left photo: Bardo Museum, Tunis, Tunisia. May 2003. Thomas Roby © J. Paul Getty TrustRight photo: Bardo Museum, Tunis, Tunisia. May 2003. Thomas Roby © J. Paul Getty Trust

Re-laid areaLeft photo: Jericho, Israel. Hisham Palace. November 1999. Francesca Piqué © J. Paul Getty TrustRight photo: Utica, Tunisia. Maison de la Cascade, room XVIII. November 2001. Elsa Bourguignon © J. Paul Getty Trust

Joints between re-laid panelsLeft photo: Beth Shean, Israel. Kyria Maria Church. April 1997. Martha Demas © J. Paul Getty TrustRight photo: Kourion, Cyprus. June 2002. Elsa Bourguignon © J. Paul Getty Trust

Metallic elementsLeft photo: Byblos, Lebanon. 1998. Thomas Roby © Thomas RobyRight photo: Israel. April 1998. Francesca Piqué © J. Paul Getty Trust

Page 7Crack

Left photo: Horvat Minnim, Israel. Mosaic no.1. September 1998. Frank Long © J. Paul Getty TrustRight photo: Horvat Minnim, Israel. Mosaic no.4. September 1998. Frank Long © J. Paul Getty Trust

LacunaLeft photo: Utica, Tunisia. Maison des Chapiteaux Historiés, room V. November 2001. Elsa Bourguignon © J. Paul Getty TrustRight photo: Horvat Minnim, Israel. Mosaic no.1, west side. September 1998. Frank Long © J. Paul Getty TrustTop drawing: Drawing by Bettina Lucherini © J. Paul Getty TrustBottom drawing: Drawing by Haim Kapschitz © Israel Antiquity Authority

CavityLeft photo: Utica, Tunisia. 2001. Bettina Lucherini © J. Paul Getty TrustRight photo: Thuburbo Majus, Tunisia. Maison de Neptune, peristyle. June 2002. Thomas Roby © J. Paul Getty TrustBottom drawing: Drawing by Haim Kapschitz, modified by Elsa Bourguignon © J. Paul Getty Trust

Page 8Detached tesserae

Left photo: Horvat Minnim, Israel. September 1998. Frank Long © J. Paul Getty TrustRight photo: Ma'ale Adumim, Israel. Martyrius monastery. August 1997. Francesca Piqué © J. Paul Getty TrustBottom drawing: Drawing by Haim Kapschitz © Israel Antiquity Authority

Deteriorated preparatory layersLeft photo: Nirim, Israel. Ma'on synagogue mosaic. August 1997. Francesca Piqué © J. Paul Getty TrustRight photo: Susiya, Israel. Synagogue, northwest corner mosaic. August 1997. Francesca Piqué © J. Paul Getty Trust

Detachment between mosaic layersLeft photo: Beth Shean, Israel. November 1999. Francesca Piqué © J. Paul Getty TrustRight photo: Horvat Minnim, Israel. Mosaic no.1. September 1998. Frank Long © J. Paul Getty TrustLeft drawing: Drawing by Bettina Lucherini © J. Paul Getty TrustRight drawing: Drawing by Bettina Lucherini © J. Paul Getty Trust

CREDITS

17www.getty.edu/conservation/

Page 9Depression

Left photo: Caesarea, Israel. November 1999. Francesca Piqué © J. Paul Getty TrustRight photo: Zippori, Israel. Mosaic of the Nile. 1998. Francesca Piqué © J. Paul Getty TrustBottom drawing: Drawing by Haim Kapschitz © Israel Antiquity Authority

Rise / BulgeLeft photo: Beth Shean, Israel. November 1999. Francesca Piqué © J. Paul Getty TrustRight drawing: Drawing by Haim Kapschitz © Israel Antiquity AuthorityBottom drawing: Drawing by Haim Kapschitz © Israel Antiquity Authority

Page 10Plant intrusion

Top left photo: Caesarea, Israel. November 1999. Francesca Piqué © J. Paul Getty TrustTop right photo: Cosa, Italy. 1998. Thomas Roby © Thomas RobyBottom left photo: Beth Shean, Israel. November 1999. Francesca Piqué © J. Paul Getty TrustBottom right photo: Horvat Minnim, Israel. August 1997. Francesca Piqué © J. Paul Getty Trust

Deteriorated repair mortarLeft photo: Utica, Tunisia. Maison de la Cascade, room XII. November 2001. Elsa Bourguignon © J. Paul Getty TrustRight photo: Horvat Minnim, Israel, Mosaic no.1. September 1998. Frank Long © J. Paul Getty Trust

Page 11Deteriorated tesserae

Left photo: Caesarea, Israel. Francesca Piqué © J. Paul Getty TrustRight photo: Susiya, Israel. Synagogue mosaic. August 1997. Francesca Piqué © J. Paul Getty Trust

Disaggregated tesseraeLeft photo: Caesarea, Israel. November 1999. Francesca Piqué © J. Paul Getty TrustRight photo: Caesarea, Israel. Francesca Piqué. © J. Paul Getty TrustBottom drawing: Drawing by Bettina Lucherini © J. Paul Getty Trust

Eroded tesseraeLeft photo: Thuburbo Majus, Tunisia. Maison de Neptune, annexe. May 2003. Elsa Bourguignon © J. Paul Getty TrustRight photo: Caesarea, Israel. January 1999. Francesca Piqué © J. Paul Getty Trust

Page 12Exfoliated tesserae

Left photo: Caesarea, Israel. November 1999. Francesca Piqué © J. P. Getty TrustRight photo: Beth Shean, Israel. Kyria Maria monastery, northwest corner of mosaic, west of large mosaic. August 1997. Francesca Piqué © J. Paul Getty

TrustBottom drawing: Drawing by Haim Kapschitz © Israel Antiquity Authority

Fractured tesseraeLeft photo: Paphos, Cyprus. June 2002. Elsa Bourguignon © J. Paul Getty TrustRight photo: Caesarea, Israel. April 1999. Cynthia Godlewski © J. Paul Getty Trust

Pitted tesseraeLeft photo: Horvat Minnim, Israel. Mosaic no.1. September 1998. Frank Long © J. Paul Getty Trust

Page 13Deposit

Left photo: Caesarea, Israel. April 1999. Cynthia Godlewski © J. Paul Getty TrustRight photo: Bet Shean, Israel. Kyria Maria. May 2000. Gaetano Palumbo © J. Paul Getty Trust

EfflorescenceLeft photo: Paphos, Cyprus. Birth of Achilles mosaic. January 1999. Francesca Piqué © J. Paul Getty TrustRight photo: Paphos, Cyprus. Birth of Achilles mosaic. January 1999. Francesca Piqué © J. Paul Getty Trust

IncrustationLeft photo: Paphos, Cyprus. January 1999. Francesca Piqué © J. Paul Getty TrustRight photo: Beth Shean, Israel. Tel Iztaba. May 2000. Gaetano Palumbo © J. Paul Getty Trust

Microbiological organismsLeft photo: Carthage, Tunisia. November 2000. Livia Alberti © Livia AlbertiRight photo: Paphos, Cyprus. January 1999. Francesca Piqué © J. Paul Getty Trust

Page 14Color alteration

Left photo: Kelibia, Tunisia. May 2003. Elsa Bourguignon © J. Paul Getty TrustRight photo: Nahariya, Israel. Bronze stains on mosaic from fire in church. August 1997. Francesca Piqué © J. Paul Getty Trust

1200 Getty Center Drive, Suite 700Los Angeles, CA 90049-1684Tel 310 440 7325Fax 310 440 7702gciweb@getty.eduwww.getty.edu