Ancient objects, modern hazards: preserving artefacts in private collections

Many people expect that items from the ancient world are safely kept in climate controlled display cases within public institutions, such as the British Museum or Smithsonian. However, ancient relics from around the globe have maintained their attraction in auction houses and antique dealerships for hundreds of years – ending up in private collections as unique household curiosities.

Above: a wide variety of ceramic and bronze artefacts from Greece, Rome and Egypt 

Without the benefit of professional maintenance, antiquities may face new challenges in their modern environments. Whether they are damaged accidentally, through atmospheric issues or exposure to disasters, such as flood and fires, we can step in to sensitively restore them. There are ways an owner can care for them too, avoiding the most preventable issues. This article will cover care requirements for these precious relics, as well as potential value and specialist restoration methods.

Above: limestone sculpture of a King, possibly Seankhkare Mentuhotep III, 2000–1988 B.C.

Owning a piece of ancient history

What can be considered an antiquity? In the most conventional sense, we would refer to an object as ancient if it has been created by a civilisation that predates the ‘modern’ world. The cut off point of this is around the early middle ages, with the period of late antiquity ending in Europe around 476 AD – the fall of the Roman Empire. If you consider objects from remote civilisations, such as the Aztecs, the date may be a lot later. Broadly, if a piece is archaeological and an intriguing link to a lost culture, it may fall within this genre.

Above: a Corinthian terracotta pyxis (mid-6th century BC), Etruscan bronze balsamarium (late 4th or early 3rd century BC), Attic terracotta amphoriskos (4th century BC) and Etruscan bronze thymiaterion bowl (late 4th century BC)

History enthusiasts have been drawn to ancient objects since the idea of collecting became a popular and fashionable hobby, reaching its height in the late 18th century – when aristocrats toured Europe to experience classical surroundings. Whether these are sculptural artworks, religious votives or household items, these physical remains give us the best insights into how our ancestors lived and interpreted the world around them.

Outside of a museum setting, artefacts make for a fascinating talking point or simply a piece that allows their owner to consider their position in the vast history of mankind.

Above: an Eretrian terracotta statue of Eros (3rd century BC), glass alabastron (late 4th–early 3rd century BC), terracotta neck amphora (5th century BC) and a Greek sculptural bust (5th century BC)

High value antiquities & market trends

The market for ancient antiques has always been strong and is often improved by the collective imagination following the release of a popular film or book franchise. The price may also increase if the item is linked to a famous ancient figure, such as an emperor or pharaoh. For many people, owning such a precious item from a classical civilisation surpasses all sense of monetary value, as they become custodians to a rare and truly unique piece of human history.

Above: details of ancient Greek marble sculpture fragments – head of a goddess (2nd–1st century BC) and head of a child (2nd century BC)

Recent auction results reflect how sought after antiquities can be. In 2018, Sotheby’s held a sale of 78 ancient items, with a total result of £5,445,000. In 2019, Christie’s New York sold a small intaglio portrait of Antinous for $2,115,000, far surpassing an estimate of £300,000. In the same year, Christies London sold a fragment of a sculpture (said to be Tutankhamen) for £4,746,250.

These are of course all very high value pieces, but the realm of antiquities is vast and very diverse. Individual items will need a specialist to give a clear valuation. Most pieces, such as small statues or vases, will still hold a fair value of at least £1000 to £10,000 depending on their quality and interest.

Above: from left to right – Grecian marble head (400–200 BC), Egyptian cat coffin (305–30 BC), Sicilian terracotta head (525 BCE) and a Vinca Idol (4500–3500 BC)

Challenges in caring for ancient artefacts 

In most cases, when we learn about antique care an expert will be referring to items that date no earlier than the renaissance period – simply due to their availability and popularity. Ancient artefacts exist in their own category of care and repair as they are not only thousands of years old but found through archaeological means. 

Above: detail from a funerary naiskos fragment, 330 BC

Whilst delftware and maiolica vases have always been kept with pride in a home or museum, ancient pieces have been through much more challenging environments – open to the weather or buried for centuries before being returned into a modern world. Materials degrade over time, stone and ceramic break into fragments and organic materials such as wood and textiles are especially vulnerable to decay, with the latter often not surviving burial and excavation at all. 

What can be done to prevent artefact damage and decay?

Specialised storage and display should be considered to assist in artefact survival, especially now that the artefact has been unearthed and removed from what is usually a stable and air-tight pocket in an artecological site. 

Metals in particular require a very low humidity environment. Terracotta and similar ceramics are porous, so should also avoid high humidity to prevent moulds from forming within the cracks and crevices. Organic materials require very low light levels, as do any items with painted elements to prevent colour loss and fading.

Beyond accidental knocks and falls, heat and moisture issues are some of the most typical varieties of damage facing antiquities. Environmental controls and monitoring will help to avoid harmful fluctuations in temperature and humidity. This should be seen as a broadly helpful level of maintenance for a home with a wide range of items requiring care, as well as preventing deterioration to ancient pieces. 

Above: examples of ancient Greek terracotta vases

Our specialist conservator recommends the following environmental conditions for each material:

Metals

Ideally under 35% relative humidity if the item is only made of metal, under 50% if materials are mixed.

Metal items should be displayed in cases made from inert materials (like perspex), as wood or chipboard can off-gas acidic compounds that contribute to corrosion. Ideal temperature range for historic metals such as bronze and brass is 16 to 22 degrees celsius. 

Terracotta & Marble

Keep within a range of 40 to 60% relative humidity. For ceramic artefacts the stability is key as fluctuations can cause efflorescence of soluble salts from within the materials, resulting in severe damage. If soluble salts are detected in ceramics, a lower range of 20-30% humidity is recommended. Ideal temperature range for ceramics is 16 to 22 degrees celsius. 

Wood

Wood should stay within the 40 to 60% range for relative humidity. The ideal temperature range for wood is 16 to 22 degrees celsius. 

Above: ancient bronze objects with natural patina – a Greek mirror disk (5th–4th century BC), Egyptian statuette of Horus (664–30 BC) and Cypriot bowl (7th–6th century BC)

Modern conservation approaches to repair

Unfortunately, older conservation efforts may have used inappropriate materials or techniques that have since deteriorated or damaged the artefact. For a modern conservator using sensitive, ethical techniques, reversing these restorations without causing further harm can be very complex but often necessary for the ongoing preservation of an object. 

Above: our objects conservator Amy working on ancient Syrian glass at The Paisley Museum – image copyright of OneRen, the trading name of Renfrewshire Leisure Limited

In terms of professional restoration, a positive for ancient items is that their materials are relatively well-researched and scientifically understood – comparatively to contemporary artworks that often incorporate new materials that have the potential to degrade quickly or react in unknown ways. We know that terracotta, metal or marble can survive for thousands of years if kept in the right conditions and therefore aim for this to continue. 

When conserving and repairing an ancient artefact, the priority is physical stability and respect for its history and cultural significance. Minimal filling and retouching is carried out on ancient pieces, whereas aiming for a seamless result is a typical restoration approach for regular antiques. Below is an ancient Jewish tear bottle where the weathered and patinated surface has been kept intact.

No alterations are made to lost or severely damaged areas, as these are typical for ancient pieces. Unlike discoloured and dirty modern pieces, for an ancient object there is effort made to preserve the patina, as this is often keeping the surface safe from decay.

It is important to remember that these pieces come from archaeological sites and will never appear in perfect condition – their built-up patina and rough edges are an expected part of their appeal. It is only when they are met with severe damage, breakages, bronze disease, staining from smoke or water damage, that we should step in to clean and repair them.

Below is a South Arabian limestone stele from the 3rd-1st Century BC. This was restored with minimal intervention, but still achieved a clear finish that will allow for ongoing stability and presentation. 

Get in touch

If you have any questions about art restoration and conservation, please do not hesitate to get in touch. As part of our service we offer a nationwide collection and delivery service as well as information on worldwide shipping to our studio.

E-mail us via [email protected] call 0207 112 7576 or fill in the form below.