The Conservation of Alabaster
||Effigy of Sir Augustine Nicolls being examined in the studio of Taylor Pearce for the Victoria & Albert Museum. The effigy was subsequently installed by Taylor Pearce in the new British Galleries.
Alabaster is a form of gypsum, hydrated calcium sulphate. Gypsum is used extensively
in plaster and mortar and is added to Portland cement to inhibit the setting period.
During quarrying or mining for this mineral, large compounded blocks would be
encountered and these were alabaster. Unfortunately, according to the technical
advisor to the Stone Federation Great Britain, John Bysouth, alabaster is no longer
extracted in the UK, or if it is it isn’t appearing on any major radar screen.
A British Gypsum spokesperson said that as far as their estates are concerned
it simply doesn’t exist in large enough quantities to make its continued extraction
However, there is still a significant mined reserve of British
alabaster left in the UK. It is owned by the Nigel Owen Organisation of Northampton.
This company, which now quarries soap stone, finds itself the owner of a spectacular
‘bin-end’ of what is probably the last of the UK’s stock above ground. Nigel Owen
himself must be the UK’s leading expert on this stone having been involved with
alabaster since 1945. He reckons that at the present rate of take up (mostly to
sculptors, who won’t thank me for divulging this information) there is a two year
supply. It is available in workman-like blocks of around a foot square.
These sculptors who are buying from the Owen bin-end represent the last knocking,
or more properly, tappings of a great British tradition that, according to most
authorities, really took off in the late Middle Ages, just before the Black Death.
too soft for external use, Alabaster is hopelessly vulnerable to the elements,
and it is too weak for building. It is so soft that it can be cut with a penknife,
making it a ready target for vandals over the ages. The very ease with which it
could be carved with finally wrought detail was one of the reasons for its popularity
for tomb sculptures and other internal devotional features, like reredoses, triptychs
and panels. The other reason, of course, was its spectacular appearance.
has a unique translucent quality that even the most desensitised individual should
be able to distinguish from marble. The colour spectrum ranges from a creamy white
(very rare) to a dark honey colour. Whatever the colour, it is made up of dozens
of veins. In colour these may be anything from dozens of shades of white to veins
of pink and reddish brown.
discovery of large accessible and workable deposits of alabaster around Nottingham
at the end of the 14th century arrived just in time to satisfy the aspirations
of all the arrivistes who had prospered in the period that followed the Black
Death. They wanted to both demonstrate their gentility in the here-and-now and
guarantee their place in the hereafter via an ostentatious contribution to their
local church. Easy to carve, easy to work, British alabaster was the ideal stone
to cope with the needs of the mass affluent.
Production from Nottingham reached the
sort of proportions that were not to be experienced again until the 18th century
in the potteries. It didn’t just stay in England. English alabaster, from small
votive statues to the Virgin to large funerary monuments and tombs, was exported
from Nottingham all over European Christendom, from Iceland to Spain. It has to
be said that the quality of much of this production was very poor, often knocked
out in pattern book style, seemingly by the yard.
|Above left: effigy of Sir Raphe Weldon (1609) at St Peter & St Paul’s, Swanscombe, Kent during conservation. Above right: The effigy of Dame Ann Carew (1605) from St Edward the Confessor’s, Romford, in the studio of Taylor Pearce after cleaning and repair. This effigy is now re-fixed on the restored monument in the church.
Late Medieval and early modern
alabaster does have its great moments, however, and most is still highly
acceptable when compared to the great Victorian alabaster carving revival when
what Alec Clifton-Taylor memorably referred to as a ‘streaky bacon’ alabaster
stalked the land along with other strange Victorian ecclesiastical enthusiasms. Alabaster is not just confined to churches however, and its use in the so-called
‘Marble Hall’ of Holkham Hall, Norfolk is regarded by some authorities as the
way that it should be used to create a spectacular, almost theatrical effect.
However, most alabaster encountered by the restorer and conservator is located
in churches, more often than not as part of a funerary monument.
CONSERVATION AND REPAIR
are certain rules of engagement that apply to alabaster, as they do to any stone
that is undergoing conservation. Firstly, whatever procedure is employed must,
wherever possible, be reversible and secondly, the aim of the exercise is not
costume drama, attempting to return the subject to its original form, but rather
to stabilise the subject in the present. Fortunately that means the virtual disappearance
of alabaster from the scene is not a problem from the conservator’s point of view.
Missing heads and extremities do not need to be replaced - that is provided they
were lost as the result of several hundred years of wear and tear or even removed
by a vandal, if it was a good class of vandal and a long time ago, like one of
Edward VI’s or Cromwell’s iconoclasts. However, the activities of modern vandals
have to be expunged from the historic record.
vandalism must be left to specialists to treat. Spray paint for example may be
readily removed using acetone or dichloromethane, but tests may be necessary to
establish which solvent is required, and skill is required to remove the pigment
||St Margaret, Barking: detail of relief part of the monument to Sir Charles Montagu (1625)
any work can be undertaken it is absolutely necessary that a condition report
and a specification of work be prepared. As often as not all the work required
cannot be undertaken on site, and the subject, or portions of it, have to be dismantled
and removed to the conservation studio or workshop.
Anybody budgeting for an exercise
of this kind should bear in mind that a dismantling process may also reveal other
problems hitherto unsuspected, that may have to be tackled. Recently conservators
from Taylor Pearce encountered a nest of wild bees in a tomb. Clearly aware of
their protected status the bees refused all the blandishments of an apiarist to
resettle them, and in the end the conservators managed, with the agreement of
the client, to strike up a modus vivendi with them, managing to work around them.
Funerary monuments account for the bulk of alabaster encountered by the conservator.
However, few of these consist entirely of this material. It is often used in combination
with marbles and sandstones, for instance, which require similar but different
main problems that alabaster presents to the conservator spring from its softness
and susceptibility to the elements, and one of the most common, caused by water
penetration, is rusting ferrous fixings and cramps. Besides staining, corroding
iron can cause the stone to fracture and ultimately render a complete monument
unstable and dangerous. The treatment is to remove all ferrous fixings and replace
them with stainless steel fixings and cramps set in resin adhesives.
the troublesome ferrous material was introduced in 19th century restorations,
as the fixings of many monuments down to the 17th century were more usually non-ferrous.
Sheep bones were a particularly popular alternative. Indeed probably one of the
biggest problems facing the conservator of alabaster, or any other stone, is botched
or failed restoration procedures carried out in the past. Even the first epoxy
resin repairs are now starting to emerge as subjects for treatment.
can be done to correct poor restoration or repair. For instance old repair plaster
can be removed from a feature and break joints filled with a matching aggregate
combined with a resin fill such as Paraloid, touched in to match the adjacent
|Detail of monument to Thomas
Witherings (1625) being cleaned
in the studio of Taylor Pearce.
Thomas Witherings was Postmaster
General to Charles I.
area where alabaster needs the greatest attention, and where the results of a
job well done are particularly gratifying, is in the cleaning and finishing processes.
It may seem unecessary to observe that this is not a job for amateurs, but there
have been a number of well recorded atrocities carried out, particularly against
alabaster funerary monuments, by well meaning incumbents and their flocks over
alabaster, however begrimed by the centuries, will clean up beautifully. One great
virtue of this stone is that, unlike marble, it rarely stains and if it does,
as often as not the stain can pass off as one of its veins. In fact the veins
are a kind of staining.
should be remembered that up until the beginning of the 17th century, alabaster
monuments were usually painted in places. Therefore it is important to carry out
a careful examination for traces of polychromy so that paint layers can be tested
for stability and resistance to solvents prior to cleaning. Subsequently any flaking
areas discovered during cleaning need to be consolidated with Paraloid resin.
should be cleaned using mild solvents. The type and strength of solvents has to
be determined by on-site tests but the most usual is a mix containing white spirit,
de-ionised water and a small quantity of non-ionic detergent. The actual cleaning
is carried out using cotton wool swabs dampened by the solvent. After cleaning
the subject should be protected by the application of a cosmolloid wax. This will
restore the magic quality to this most agreeable of stones.
article is reproduced from Historic Churches, 2001
COX is the Director of Taylor Pearce
Restoration Services Limited, a firm of conservators specialising in the conservation
and restoration of stone statuary and ornaments, architectural ceramics, mosaic
work and church monuments.
Lime Mortars and Renders
Statuary and sculpture
PRODUCTS AND SERVICES
Church repair contractors
Statuary and stone carving
Communications Limited 2016