Sticks and stones: a day in the life of a finds specialist

My name is Dawn McLaren and I am a finds specialist here at AOC Archaeology Group, based in Loanhead, Scotland.  On a day-to-day basis I’m involved in analysing artefacts recovered as the result of archaeological excavations undertaken by AOC’s fieldwork team.  Most of the objects that I have the privilege of working on come from archaeological sites in Scotland but as we have offices in York and London I’m also involved in identifying finds from digs across England.  My job is to identify any artefacts uncovered and this means figuring out what material the objects are made from, what date they could be and what they might have been used for.  In order to get as much information from the finds as possible, I work closely with AOC’s fieldwork team to understand as much as I can about the context of the finds on site and their possible significance, as well as working with AOC’s conservators to ensure that the objects are cared for properly once they come out of the ground.

Examining the grinding face of a rotary quernstone

Dawn examining the grinding face of a rotary quernstone

To give you an idea of the range of finds that I deal with, in the last few weeks I’ve been looking at a some Neolithic pottery from a site in northeast Scotland, some ironworking waste from a Roman site in southeast Scotland and a post-medieval assemblage of iron and worked bone from an urban site in Edinburgh. As I said in my 2012 Day of Archaeology blog, each artefact I meet presents its own challenges and it definitely keeps me on my toes!  They all have their own story to tell, so let’s see what’s in store today….

Today I’m examining a small group of worked stone objects from a Roman site in southeast Scotland. My first step is always to examine the individual objects in detail to allow me to observe any surface markings that might be tool marks left from manufacture of the object, wear from use or damage sustained to the object before it was deposited.  Some types of stone tools are more recognisable than others, such as this wonderful fragment of a rotary quernstone (see images), but this detailed approach allows me to categorise the wear and helps me to create, where possible, a biography of the artefact- from its manufacture to its deposition after its use had ceased.

Analysing a Roman quernstone fragment

Analysing a Roman quernstone fragment

The next stage is to catalogue the objects and this means describing each artefact in detail and taking measurements of each item.  Assisting me in this task is Marissa, an overseas student who I’m supervising here at AOC Archaeology this month on an Arcadia Internship.  The internship aims to provide training and experience in post-excavation work and is an important part of AOC’s commitment to making archaeology accessible to a wider audience and to provide valuable experience to promising students.

Taking measurements of central socket

Taking measurements of central socket

Having now looked at all stone objects within this particular assemblage, the star find for me is definitely this wonderful quernstone fragment!

Roman quernstone fragment

Roman quernstone fragment

These rotary quernstones would have been used as a pair – an upper and lower stone – to grind grain into flour. The lower stone would remain stationary and the upper stone would be turned by hand as the grain was fed down a central hole in the upper stone.  This particular stone represents approximately one half of a lower grinding stone and has a clear series of vertical grooves decorating the edges of the stone and a convex grinding face which has been deliberately dressed to make a rough surface for the grain to be ground against.  What is really interesting about this example is that the style of the quern mimics imported Roman lava quernstones but is almost certainly made from local sandstone.

For more information on our post-excavation services please check out our website:



Iron Age Slag – No Puns Please!

I’m Dawn McLaren and I’m a finds specialist at AOC Archaeology Group based at Loanhead, Scotland. On a day-to-day basis I’m principally involved in the post-excavation analysis of artefacts recovered as the result of developer-led excavations ranging from early prehistoric through to post-medieval in date. To give you an idea of the range of finds that I deal with, in the last couple of weeks I’ve been looking at coarse stone tools and querns from an Iron Age settlement, some pottery from a Bronze Age burial and post-medieval metal finds from an urban site in Edinburgh. It definitely keeps me on my toes!  

Today I’ve been examining some later prehistoric ironworking waste from a multi-phase site at Beechwood, Inverness and I’m really excited about what it is telling us about metalworking on the site.  The site, which was excavated by my colleague Rob Engl and others, revealed several Bronze Age/Iron Age timber roundhouses, palisades and enclosures together with evidence of Neolithic settlement.

Dawn identifying slag from Beechwood

Starting from the beginning, what is ironworking waste?  Basically, it is the non-iron component of ore that is separated out from the iron during smelting and smithing but there is inevitably other associated debris such as bits of ceramic hearth lining and vitrified stone which don’t necessarily need to be connected to metalworking. I’m terribly over simplifying, of course, but I hope this gives you an idea. Visually, this material doesn’t look like much, I admit! It often looks like rusty or glassy shapeless ugly lumps. But I’ve been trying for years to convince people that it’s really interesting and can tell us a lot about metalworking technology.

My first step is always to visually examine (macro and microscopically) the individual pieces looking at the colour, texture, shape and how melted and fused the material is. Another important part of the initial identification is to determine whether the material is magnetic. All of this information helps me to split the assemblage into broad categories: what is ironworking waste and what has been formed as the result of another pyrotechnic process, what is diagnostic of iron smelting and what might be bloom- or blacksmithing debris. Once I’ve identified the individual pieces, I record all the details (e.g. weight, quantity of pieces and measurements) into a spreadsheet so that I can feed in the contextual data later.

Small smithing hearth bottom from Beechwood

I’m pleased to say that the assemblage from Beechwood has a bit of everything!  It’s not a large assemblage but so far I’ve identified several smithing hearth bottoms and fragments of smelting waste so that I can say that both processes were taking place on or around the site.

Smelting slag from Beechwood

Now that my catalogue of the slag is complete I’ve started to look at where the pieces were recovered from. The excavations at Beechwood covered a very large area and I can see from my initial examination that the ironworking debris is focused in two quite disparate parts of the site. One area, which we’ll call A, includes a possible metalworking hearth or furnace associated with smelting slags and the other area, B, which is quite a distance away and must represent a separate focus of activity, has small residual amounts of both smelting and smithing debris. We’ve already had some of the pits and postholes from these areas radiocarbon dated and those associated with the ironworking waste have provided wonderful Iron Age dates.

Looks like my task for tomorrow is to see how the Beechwood evidence fits in to other Iron Age metalworking sites in the area!

For more information on our post-excavation services please check out our website:

Conservation of Archaeological Metal Assemblage

I am an objects conservator at AOC Archaeology group, a commercial archaeology company based in Loanhead, Midlothian, Scotland. There are only two of us in the department so we are kept very busy and are involved in all sorts of projects with every day being completely different. We conserve and stabilise all the finds that our archaeologists in the field excavate.  Often we are the first non-archaeologists to deal with freshly excavated materials and we are constantly ensuring that the materials gain their archaeological potential.

At the moment I am conserving a large number of finds from two sites excavated by our London office. The purpose of the conservation is to stabilise the finds for the long-term archive as well as possibly reveal new details on the surface of the objects, helping the specialists identify and describe the finds.  The finds are all metal – iron, lead and copper alloy with a large number of Roman coins and many coffin nails.

All the artefacts were covered in thick layers of soil and corrosion obscuring the surfaces and masking any detail. Following x-raying of the finds, I cleaned the iron artefacts using an air abrasive machine and the copper alloy items using mechanical methods (scalpel, bamboo skewer) carefully under a binocular microscope.

Me cleaning a copper alloy spoon under the microscope


Roman coin after conservation


This morning I have been finishing the last few objects and taking after treatment photographs. This afternoon I will be documenting the treatment of each object. As the objects were excavated in London we have to follow a specific documentation procedure set by the Museum of London. Each object has a A5 proforma card with specific information about the find, its condition and how it was treated.

While I have been working in the lab Alan Braby a freelance illustrator has come in to do a recorded drawing of one of the amazing Roman altars that we have been conserving recently. If you would like to find out more we set up a blog about the conservation work we have done on these two Roman altars excavated at Lewisvale Park. Here is the link: