§ 2. MOSAIC.
The mosaics of figures exposed at the time of Fossati’s repairs are many of them figured by Salzenberg, although his harshly coloured diagrams can but very inadequately represent the beauty of the originals. We give here his descriptive text in a slightly condensed form as a basis for our own remarks. Dethier[374] asserts that only a part of the mosaics discovered were published by Salzenberg, and that Fossati preserved others inedited in his portfolios.[375]
The mosaics are formed of glass of various colours cut into small pieces and applied to the vaults with a cement. The gold mosaic was made by laying leaf gold on the glass, which was then covered by a thin film of glass to protect the surface. Silver mosaic was made in the same way. The gold was used, in spite of its apparent abundance, with great economy. For instance, in vertical spaces high up and only visible from almost immediately beneath, the tesserae are arranged in horizontal rows at a distance of two or three tesserae from each other with their upper edges projecting. The projecting edge of the lower row hides the bare space between it and the row above. There is thus a saving of more than half the material, and great play of light is obtained. The tympana of the aisles are covered in this way. The coloured tesserae are set in the usual way, as the difficulties involved by the other method in the curves of the ornament would outweigh the saving of material.
Besides gold and silver, red, blue, and green are the principal colours; though others are used in the heads of the figures. The vaulting throughout was covered with a background of gold, on which are conventional patterns that follow the forms of the construction. Some of the spaces have representations of figures.
In the bands of ornament are gamma-crosses [swastikas], hearts, leaves, and crosses, placed in circles, squares, and other figures. There are no sharp arrises to the vaults, but patterned bands are placed on the rounded edges.
The vault of the narthex has its wide transverse bands adorned with gamma-crosses. In the domed portions between the transverse arches are diagonal bands which culminate in a circle inclosing a cross.[376]
The vaults of the gynaeceum, perhaps because they were visible from the nave, are more elaborate than those of the aisles below.[377] Salzenberg’s Plate xxv. shows the western dome on the south side, on which is represented the descent of the Holy Spirit: the arches have the same ornament as those below.[378]
Details of the dome are given in Salzenberg’s Plate xxvi. The edges of the ribs and window openings are covered with bands of ornament. The faces of the ribs have alternate squares and crosses, which decrease in size as they get higher. The central space has lost its figure subject, but it is surrounded by a wide border.[379] The sides of the window openings are lined with silver mosaic. The lower part of the dome is not decorated, as the projecting cornice hides it from below.[380]
The edges of the exedra-conchs have bands similar to those on the great arches, and the same pattern occurs again on the edges of the eastern barrel vault, and the bema apse.[381] The rest of the decoration of the surface of the apses has disappeared.
Over the centre door from the narthex to the nave is represented Christ on a throne, holding a Gospel open at the words, “I am the Light of the world: Peace be with you.” A monarch is prostrate before him, and in medallions on either side are Mary the Intercessor, and Michael the Protector.[382]
The nimbus of Christ has three rays, and His hand blesses in the Greek manner, by which the fingers represent the initial and final letters of Jesus Christus. The undergarment has broad gold stripes worked on it, and the lights are given in silver; it seems to be of silk, the upper garment appears to be of a white woollen stuff.
The great western arch has a medallion of the Virgin at the crown, and full lengths of Peter and Paul at the sides, Peter on the south; however, only a few remnants of these figures are now left. The border which surrounds the medallion of the Virgin has colours of the rainbow, the circle of her halo is red; the flesh colour is fair, and the eyes are blue. The veil is blue, with a gold cross, and the cloak is also blue. Under the veil is a kind of band round the head, like that which the Spanish Jews of Constantinople wear; it is of a blue green colour with dark stripes; the hair is not visible. Her nimbus has three silver rays on a gold ground; her hands rest on the shoulders of the Child, whose right hand blesses, while the left holds the book of the Gospel.
Peter’s face is dark, the nimbus is blue, the garment is bluish green, and the gold rod, surmounted by a cross, has red and blue bands. He thus has the same insignia as the St. Peter on the Ciborium Curtain, and it is this which, in the mosaic, identifies the figure as Peter, for there is no inscription. Porphyrogenitus, in his life of Basil, mentions that when the western arch was restored the pictures of the Virgin, and the Apostles Peter and Paul were placed there by that emperor. The figure of Paul has an upper garment of green with silver lights, and the undergarment is a greenish yellow. The whole figure is about seventeen feet high, but the head is wanting.[383]
On the large semicircular walls beneath the northern and southern dome-arches are a number of figures in mosaic. The seven arched recesses were filled with representations of martyrs and bishops; above, between the windows, were six smaller figures of prophets, and a larger figure at each end. At the height of the upper row of windows were probably the archangels, but of these only the feet remain.
The figures that now exist are the following. In the recesses on the south side, the second from the east is Anthimos, Bishop of Nicomedia, martyred in 311: in the third is Basil, Bishop of Caesarea, martyred in 379.[384]
The fourth recess from the east has Gregory Theologos, Patriarch of Constantinople from 378 to 383. The next figure is Dionysius the Areopagite; who was converted by St. Paul, and became, tradition says, Bishop of Athens. In the sixth recess is Nicholas, Bishop of Myra, who died in 330. This figure is partly destroyed. The seventh, is Gregory, Bishop of Armenia, who died in 325.[385]
The figure of Isaiah, which is to the east of the row of windows, had been covered up (when Salzenberg made his drawings), but it was described by Fossati as having an undergarment of green with silver lights, and over it a cloak of a white woollen stuff. The right hand pointed towards the bema, and in the left was an open scroll with the inscription, “Behold, a Virgin shall conceive and bear a son.” Under the figure was a monogram.[386] Higher up again on the same wall was the inscription:—
ΑΙΓ....ΤΗϹΑΘΑΝΑΤΟΥ ϹΟΦΙΑϹ
ΗΡΑ....ΤΟΥΚΕΑΚΗΡΑΤΩΝ....
The recesses of the north wall have no mosaics [see below, p. [287].]
At the height of the windows, the first figure beginning from the east is Jeremiah.[387] The undergarment has stripes of blue and red, and the upper represents a russet-coloured woollen stuff. The right hand blesses, the left has an open roll [with the inscription shown in the plate, “This is our God; no other shall be compared to Him.”].[388]
The figure between the first and second window is probably Jonas, as ΑϹ still remains on the right side of the head, and there is only room for three letters on the other side. The undergarment is a greenish blue with silver lights, and has broad red stripes. The nimbus is blue.
Over the head of this figure is found the remnant of an inscription ΝΤΙΔΟϹ. This may have belonged to one of the figures above, of which a sandaled foot and edge of a garment alone remain. The foot does not stand upon green earth, like the prophets below, and therefore probably belonged to an angel. Only a part remains of the third prophet from the east, which was inscribed Habakkuk.[389]
The mosaics on the soffite of the eastern arch were covered before drawings were made. At the crown is a medallion with a white ground. In this is a low throne of gold, with two green cushions upon it; over them is thrown a blue cloth with a white hem, and upon that is placed a golden book. Above is also a gold cross with three arms; the middle one is the longest, and at its intersection with the upright member is a circle. On the south face of this eastern arch is the figure of John the Baptist, with long hair, and a brown shaggy garment; his right hand blesses, and his left holds a cross with three arms. Opposite, on the north side is the Virgin, with uplifted hands in the attitude of prayer. She has a white undergarment, bound with a golden girdle, a red upper garment, and a veil of a green-blue, with a gold hem. Under her is John Palaeologus, who restored this part, and to whose time these figures and designs certainly belong. The emperor wears a crown, with strings of pearls on either side. He has a closely fitting undergarment of gold, decorated with pearls and embroidery. A magnificent cloak hangs down from the left shoulder, and round the neck and breast is a kind of broad gorget richly embroidered. In his right hand is a sceptre, and in his left a roll.
The archangel on the south side of the bema vault[390] has a globe in the left hand, and a staff in the right. He is clad in white, with imperial red shoes. The arch of the apse bears an inscription, which ends with the letters ϹΕΙΕ ΠΑΛΙΝ.
On the conch of the apse is the Mother of God upon a throne, holding the Child between her knees; her upper garment, which is blue, conceals the whole figure, except that at the breast, under the arm, and above the feet, the white and gold garment beneath is visible. The Child has his right hand uplifted and his left against his breast. He wears a white garment, with a gold girdle. His hair falls down freely, and the nimbus has three streams of light. The throne is gold with red ornaments, but is without a back, and the footstool is of green silk.
In the dome pendentives are Cherubim with six wings. Each head is four feet two inches high. The upper feathers of the wings are a light green, and the under feathers brown.[391] The great centre-piece of the dome, which, according to Du Cange, represented Christ as Judge of the World seated upon a rainbow, no longer exists.
Only one of the domes of the gynaeceum preserves its mosaic ornament of figures. This[392] represents the descent of the Holy Spirit. Only a part remains of the throne in the centre; on it is a green cushion, and a blue cloth with gold patterns. Groups of spectators fill the pendentives of the vault.
Above the doorway which leads from the western gynaeceum to the chambers over the south porch, are remains of figures, which can no longer be identified.[393] In the ceiling of the chamber over the stairway is a design of green tendrils on a gold ground.[394]
The small dome in the chamber which opens out of the western buttress of the south side on the first-floor level has four angels with uplifted hands, supporting a medallion in the centre. This design is similar to that in the side chapel at S. Prassede at Rome.
“The figure representations belong to the time of Justinian, though the Silentiary, otherwise so accurate, does not describe them.”
First Scheme.—A reading of Salzenberg’s notes on the figure mosaics will show how little ground there was for his impression that these belonged to the time of Justinian, which the last sentence expresses. Several of these mosaics are dated as being parts of restorations. Thus he shows that Basil I. placed figures on the arch of the great western hemicycle, and that those of the great eastern arch are the work of Palaeologus.
The subject has been much obscured by insecure assumptions and inexact assertions. Labarte, who was one of the first to doubt that Justinian was intended by the figure of the kneeling emperor before Christ over the Royal Door, thought that the Silentiary described figure-mosaics as covering the interior.[395] Gerspach in La Mosaïque calls the emperor ‘Justinian’ and appears to mistake the Pentecost cupola for the great dome. In regard to the date of the lunette containing the emperor, Labarte suggested that it was a work of the seventh century, and that the emperor was Heraclius.[396] Woltmann and Woermann placed it still later and write, “There is no kind of resemblance between the beardless portrait of Justinian at Ravenna and this bearded, gray-headed man. It is more likely to be Basil I. the restorer of the western apse, and this opinion is supported by the miniatures of his time.” The pilgrim Anthony seems to refer to it as Leo the Wise, but the Russians ascribe so many works to this emperor without reason that this is inconclusive. The forms of the letters in the inscriptions, however, show that the mosaic is late. Bayet,[397] who has considered the mosaics afresh, and thinks the silence of Paulus is conclusive as to the absence of figure-mosaics when the poem was written, about 562, himself seems to misread some parts of the poet’s description; thus he thinks patterns in mosaic are intended in lines 607-612. The animals of the atrium may possibly have been of glass mosaic: but we think it more likely that inlaid marble like the dolphins of the interior ([Fig. 49]) is intended. The baskets of fruit, branches with birds, and the golden vine in the church, spoken of in lines 668, &c. seem to refer to the carved and gilt surfaces of the spandrils of the arcade, not to the mosaic, as Bayet supposes.
The figure scheme, so far as it can be traced, closely agrees with the Byzantine Manual of Painting: and the subjects and treatments can be associated with work in other churches of the ninth and tenth centuries which have in several cases almost identical designs. Altogether it may be doubted if a single figure belongs to a time anterior to the iconoclastic period of the eighth century.
We believe the original scheme of decoration is best accounted for without figures, and even if this were not so, we can hardly believe that in the Patriarchal Church at the door of the Palace figures would have lasted through the reigns of the iconoclastic emperors and patriarchs, as they may well have done in remoter churches where the clergy were on the other side. Leo issued his first decree against images in 726. Its purport was not, as is often stated, that pictures should be hung higher in the churches in order that people should not adore them by kissing: “it commanded that they should be totally abolished.”[398]
Fig. 70.—Mosaic of small Vault Compartment next the Bema.
It is well known that a figure of Christ over the entrance to the palace was destroyed by Leo the Isaurian. Dr. Walsh, who was chaplain to our embassy at the Porte about 1820, writes, “There stood till very lately in Constantinople an inscription over the gate of the palace called Chalces. Under a large cross sculptured over the entrance to the palace were the following words:—
“‘The emperor cannot endure that Christ should be represented (graphes) a mute and lifeless image graven on earthly materials. But Leo and his young son Constantine have at their gates engraved the thrice-blessed representation of the cross, the glory of believing monarchs.’”[399]
In 768 Nicetas, the patriarch under Constantine, Leo’s son, is said to have destroyed “the images of gold mosaic and wax encaustic” in all the churches of Constantinople.[400] And in the life of Theophilus we read, “throughout every church the figures of the saints were destroyed, and the forms of beasts and birds were painted in their places.”[401]
It is quite certain from Procopius and the poem of the Silentiary that the vaults of Justinian’s church were covered with mosaic. They both describe the brilliance of the gold glittering surface, but do not mention any figures. In such detailed descriptions this silence goes far to show that there was originally no storied scheme of imagery, like that which the Poet so fully traced out on the curtains and iconostasis. It seems equally certain that where, describing the dome on the strong arches, overhanging the interior like the firmament which rests on air, he says, “at the highest point was depicted (epigraphe) the cross, Protector of the City,” we are to understand that a great cross in mosaic expanded its arms on the zenith of the dome, and that the background was strewn with stars. Now this is a well-known scheme, and it is found at an earlier date in the chapel of Galla Placidia at Ravenna, and later it is mentioned by Porphyrogenitus in a description of a domed apartment in the palace. The stars on the dome are more than once referred to in the poem (page [36]), and it is probable that the surfaces between the ribs as well as the central circle had gold stars set in azure, the ribs being of gold; nothing less would seem to justify “the firmament of the roof its rounded expanse sprinkled with the stars of heaven.”
It is evident that, however easily figures and pictures might be added here and there at various dates, the church, being once incrusted with mosaic, would at no subsequent time have had the enormous areas of tesserae removed to be again renewed.
It follows that the ground, and any patterns evenly distributed in every part of the vaults, are assuredly of the first work. First among such designs is a jewelled cross thirteen feet high, which is blazoned on both ground floor and gallery vaults, and which must have been repeated some twelve times twelve. We give an outline of one of the smallest vault compartments in the church, the irregular space to the east directly south of the bema: here three of the crosses can still be seen through Fossati’s colouring, their interlocking arms spreading over the whole field. This form of cross, with lobed ends, is found set in a circle of stars, in the mosaic apsoid of S. Apollinaris in Classe. ([Fig. 70].)
A similar argument applies to other forms which occur with equal frequency. A square panel of ornament which alternates with the crosses, certain diapers, the bands up the edges of the aisle vaults, and the small circles each containing the six-armed cross or monogram at the centre of these compartments, would all seem to be parts of the original work, and these simple elements we believe formed the first scheme of decoration. Texier figures a mosaic from Salonica made up of crosses. The splendid simplicity of such a scheme seems entirely in harmony with S. Sophia, for even figures would disturb the beauty of the expanse which at each movement glitters like a web of golden mail swayed by a breeze.
Later Mosaics.—For the mosaics displaying figures we refer back to Salzenberg’s description. Much further information might have been gathered if he had given copies of the inscriptions which exist, in however incomplete a state. His section (Plate x.) shows that a long inscription surrounded the arch of the apse, but in his text he only gives the last few letters ϹΕΙΕ ΠΑΛΙΝ; this possibly belonged to the words ἀνεστήσειε πάλιν, “Set up again,” and the whole may have contained the name of the emperor under whom this restoration was effected. (See below, p. [287].)
On the great lunette of the wall of the south side also, where the tiers of saints and prophets seem a part of a scheme representing the Church triumphant, or a Benedicite, two monograms occur (see Salzenberg’s Plate ix.); only the first, which reads ΚΥΡΙΕ, is figured in the text; it is evidently a part of the well-known invocation, ‘Lord, help,’ which requires the name of an emperor or artist to complete it.
An inscription between these monograms is partly given in the text; and supposing it to be correctly rendered the whole probably read “Lord, help” (name who painted this wall) “of the Immortal Wisdom” (with the figures) “of the saints”.
The entire later scheme of the mosaics must have corresponded closely to that in the New Church in the palace built by Basil, which is described by Porphyrogenitus. Here, at the centre of the dome, was the human form of Christ embracing the whole world in His regard; below were ranges of angels. In the apse was the figure of the Virgin with arms uplifted in prayer, “a choir of apostles, martyrs, prophets and patriarchs filled the other spaces of the whole church.” This in turn resembles very closely the iconography at S. Luke’s.
Fig. 71.—Restoration of Throne at Crown of Pentecost Dome.
The following instances may be given of the agreement of the mosaics at S. Sophia with the instructions of the Painter’s Manual. For example, it directs that over the door of entrance from the narthex Christ be represented throned, holding the Gospel open at the words, “I am the Door: by me, if any man enter in, he shall be saved.” At each side the Virgin and the Prodromos are to be represented. The figure to Christ’s left at S. Sophia, called Michael by Salzenberg, Grelot tells us was the Prodromos and he probably followed the traditional ascription, although the type seems to agree better with an archangel.
Again, “Inside the Sanctuary at the centre of the vaults draw the Virgin seated on a throne holding Christ as a little child.”[402] This exactly describes the apsoid mosaic at S. Sophia. The cupola of the gynaeceum, representing the descent of the Holy Spirit, is also in close agreement with the directions given in the Manual:—“The Holy Spirit is seen in the form of a dove, twelve tongues of fire go out from it and rest on the apostles.” This subject is treated at S. Luke’s in a manner almost identical to that at S. Sophia, and it is also found in a dome at S. Mark’s.
Diehl in his examination of the mosaics at S. Luke’s has pointed out that the central circle of the Pentecost cupola at S. Sophia as shown by Salzenberg in Plate xxxi. is quite insufficient to have contained the figure of Christ as shown in the restoration given on Plate xxvi., and that consequently the Holy Spirit as a Dove really occupied this position as at S. Luke’s. In [Fig. 71] we give an amended restoration of this centre; it will be seen from Salzenberg’s text that he had no evidence for a figure. The two angels above the sanctuary are described by Salzenberg as bearing lances or banner poles; these were doubtless surmounted by Flabella bearing the words
ΑΓΙΟϹ
ΑΓΙΟϹ
ΑΓΙΟϹ
as at S. Luke’s and Nicaea.[403] There is a very similar angel holding a flabellum of this kind in the tenth century Menologium; and the words Holy, Holy, Holy, are directed to be put on flabella in the manual.
Again the Manual says, “At the summit of these vaults (opening from the dome) draw the holy Veil to the east and opposite to it the holy Cup.” Now in Grelot’s view of the interior, made when many of the mosaics were still visible, he shows a large square mosaic at the crown of the bema vault directly over the altar, which he says was “the picture of Christ’s face upon a napkin called Veronica.”
The representation of the throne at the centre of the soffite of the eastern arch (see p. [277]) is one of the most beautiful symbolisms of Byzantine art. At Nicaea the same design occurs in a similar position on the triumphal arch, and it is inscribed ΕΤΟΙΜΑϹΙΑ ΤΟΥ ΘΡΟΝΟΥ. This “Preparation of the throne” referred to the second coming of Christ. Our figure represents a throne of this kind which we offer as an illustration of that at S. Sophia; it is based on a throne inscribed Η ΕΤΗΜΑϹΙΑ which appears on the cover of a Byzantine Gospel book at S. Mark’s.[404] The small dome of the little chapel on the first floor, Salzenberg says, resembles a dome at S. Prassede. The latter is a work of the ninth century.[405]
Fig. 72.—Restoration Throne at Crown of Great E. Arch.
Salzenberg’s description seems to account for all the figured mosaics mentioned by Grelot (1680) except the “Veronica over the sanctuary.” When Grelot made his drawing there was no figure at the crown of the dome but only the bands rising to the central wreath. Clavijo however writes, “The vault of the square is covered with very rich mosaic work, and in the middle of the vault high over the great altar the image of God the Father very large is wrought in mosaics of many colours; but it is so high up that it only looks the size of a man or a little larger though really it is so big that it measures three palmos between the eyes.” This must be the Pantocrator of the Manual—“draw near the summit of the cupola a circle of different colours like a rainbow seen on clouds in rainy weather. In the centre represent Christ with the Gospel and this inscription, Jesus Christ, the Almighty.”
Since the above has been in type we have found a pamphlet published by the brothers Fossati in 1890,[406] describing a collection of drawings of S. Sophia, shown by them at Milan. From this we gather the following additional particulars of the mosaic subjects.—Over the door of the south porch “was a remarkable mosaic representing the Virgin and Child, to whom Justinian presents the Church and Constantine the City.”—A representation of Christ, the Virgin, and S. John, forming the Trimorphion (Pantocrator, Pantochrante, Pantepopte.)—Two groups of the Fathers of the Church, thirteen altogether: Ignatius Oneos, Methodius, Ignatius Theophorus, Gregory Thaumaturgus, John Chrysostom, Cyril, and Athanasius. [These must occupy the seven recesses on the north window-wall, as the six others agree with those given by Salzenberg on the south side].—The Pantocrator on a throne [? supposed centre of Pentecost dome].—John Palaeologus [? with the Virgin on north side of great east arch, p. [278]].—John Comnenus and Irene with the Virgin between them.—Constantine XI. and Zoe with Christ between them.—Alexius Comnenus X. or XI.—Alexander, the brother of Leo [some of these also were doubtless on the great east and west arches].—Three Virgins.—S. John with six apostles surrounded by cherubim [? in higher part of one of the window-walls, p. [277]].—Prophets [? of window-wall, p. [276]].—A circle with colossal Pantocrator [? the destroyed centre of the great dome].—Different emblems with Greek and Latin descriptions. Besides these, a drawing of Cherubim “saved from the Atrium Portico” is mentioned; and the inscription on the arch in front of the apse is given as follows, and may be compared with Salzenberg’s Plate x.:—
ΗΙΑΝΙΡϹΕΙΑΡ ΗΡΑΝΘΕΟΗΑΡΙΗΑΡ ΘΕϹΙϹΗΝΑΝΕΑΙϹΕΙΕ ΠΑΡΙΝ.
The earliest description of the mosaics entering into any particulars is that of Dr. Covel’s MS. 1670-7 in the British Museum. “In those cupolas [of gynaeceum] are imagery of Saints and the story of the Bible which the Turks have in many places quite defaced and plastered them all over; in other places only scratched out or disfigured their faces as the cherubims in the corners under the great dome.” He then enters into details of the pentecost dome which was the only figured vault entire; and then describes mosaics in the western gallery not otherwise mentioned. “In the sides of the second window [from the south], is Christ coming up from Jordan and the Descent of the Holy Ghost with these words, Matt. iii., 17:—ΟΥΤΟϹΕϹΤΙΝ, &c., on one side and over against it, Christ between Moses and Elias with these words, Matt. xvii., 5:—ΟΥΤΟϹ, &c.” The window jambs of the western gallery are now plastered, it is probable that a series of mosaics of the life of Christ covered them. Up to 1840 every visitor seems to have been offered tesserae, which for better assurance were broken out before his eyes. The Italian MS. of 1611 also in the British Museum (Harl. 3408), after saying that the walls of the church were lined with marble adds, “the porch as well, except that this is all worked in mosaic with growing leaves of great beauty down to the pavement of the porch.”[407]
Fig. 73.—Mosaic Tesserae, actual size.
Signor Boni has noticed that some of the gold tesserae at Parenzo are inserted at an angle of 30° to the plane of the wall, so as to be normal to the line of vision, just as Salzenberg describes at S. Sophia; the same thing occurs at the Dome of the Rock. This, besides saving the material, aided in flashing the light, a property of the gold tesserae which was much valued, as several inscriptions from the mosaics show.[408] In S. Maria in Domnica, the apse—“Nunc rutilat jugiter variis decorata metallis,” again in S. Maria in Trastevere the vault “divini rutilat fulgore decoris,” and at S. Paulo fuori le Mura the mosaic—“fulget fulgente decore.”
We have examined a handful of gold tesserae from S. Sophia through the kindness of Mr. James Powell. The cubes average a quarter of an inch in size, the glass is yellowish, slightly amethyst or dark green. The surface layer equals stout paper in thickness. At the back of the tesserae a dusty red appears, which under a glass proves to be of powdered tile. This roughens and adheres to the surface of the glass, which was evidently sanded with the powder while in a molten state, and of course before it was broken into morsels. The first purpose of this without doubt was to increase the hold of the cubes to the cementing material, but the reddening—almost like a coat of vermilion paint—may probably have assisted the gold to show out better than if the tesserae had been fixed without it into the perfectly white stucco which forms the bed. The cementing material was an inch or more in thickness, formed of lime with broken reed for binding, and a considerable amount of crushed white marble, in the part next the mosaic at least.