Originally this post was going to present all the copper alloy jewelry recovered and conserved from the Cardiff Castle excavations. It was quickly realized that this would be a huge task based on the number of finds. As a result I have split the original post into three smaller posts, each looking at specific object types: bracelets, rings and other objects. This post covers finger rings which were identified as rings or finger rings by archaeologists prior to conservation. Most if not all of these are probably finger rings with the possible exceptions of SF 0348 (see below).
The finger rings recovered from excavations and conserved can fit into four broad categories based on style and object condition. It should be noted that these styles were constructed for the purpose of this blog and are not a reflection of convention in archaeology. I include object condition as a criterion for the simple reason that an incomplete finger ring may preclude it from a category that it might well fit into if complete.
The conservation goal for these objects is simply to clean for identification and preservation, and report on any discoveries. The cleaning was conducted under a binocular microscope using a fresh scalpel blade to remove soil and copper corrosion, such as malachite (a copper carbonate) and extruded cuprite (a copper oxide), to reveal the ‘original’ surface of the object. Ethanol impregnated cotton swabs were used to remove loose material from the surface. The objects were coated with two coats of 10% (v/v) Incralac in toluene after cleaning.
It should be noted that the simple acts of using a scalpel blade and cotton swabs on the archaeological materials is grounded on a foundation of understanding regarding the technology, chemistry and corrosion processes of, in this case, copper alloys. Please do not use any information contained within these blog posts as a guide on how to clean archaeological objects unless the user has a similar level of understanding, training and experience.
Round Cross-Section Finger Rings
SF 0061, SF 0348, SF 0538, SF 0576, SF 0974
Five finger rings, either complete or fragmented (SF 0061 and SF 0348), fit into this category. All of the rings were covered in loose soil with some minor quantities of harder concreted soil and all exhibited some form of corrosion deposits on the surface. Upon cleaning, ring SF 0348 exhibited a dark green patinated surface with some pitting. The inner diameter of the ring is 30 mm (my wedding band is 19 mm inner diameter). This makes for the biggest ring in those presented here. It could be a large finger ring or possibly a harness ring. Ring is SF 0538 had similar patination and pitting to SF 0348. The surface of SF 0576 revealed similar pitting but lighter green colour. SF 0061 was similar to this but the colour is more buff. The surface of SF 0974 showed some areas of a green patinated surface but a lighter powdery textured surface underlying it was more extensive. This is not powder on the surface but rather a powdery or silty textured surface. This surface was noted on some of the bracelets mentioned in the previous post. It is not suspected of being ‘bronze disease’ as no additional ‘powder’ was produced during the several months that it was in our care. The object will be monitored to ensure that the object is not actively corroding.
Penannular Finger Rings
SF 0217, SF 0335
Two rings fit into the penannular (meaning the form of a ring with a small break in the circumference) category. These rings were covered in loose soil from the burial matrix. Ring SF 0217 contained a plug of dirt within the ring. This incited a slight feeling of apprehension as it gave the appearance that the plug of soil was supporting the entire structure of the ring. The condition of the uncleaned ring also fed into this fear as it was mottled light and dark green mixed with the soil on the surface. As it turns out, this was completely misleading as the ring was structurally sound (meaning it was not about to collapse) when the soil was removed. The surface consisted of a dark green patina broken by corrosion warts. The warts were retained as removal would most likely reveal pitting below. The ring is a highly eccentric ellipse in cross-section. Highfalutin words meaning generally rectangular with convex surfaces. Cleaning of Ring SF 0335 revealed a greenish-brown patinated surface with some warts. The ring is generally round in cross-section but were tapered to a point at the termini.
Strap Finger Ring
The ring had fragmented into three pieces. Each fragment was covered in soil from the burial matrix. One of the fragments also exhibited thick copper corrosion deposits. Cleaning revealed that two of the fragments could be joined. These were adhered using 40% (w/v) Paraloid B-72 in acetone. The surface is pitted with corrosion warts. The warts were retained due to the fragile nature of the ring body out of fear that the ring could fragment more. The ring is rectangular in cross-section with convex surfaces. This ring is similar to SF 0217 discussed above but was relegated to its own category due to it lacking termini.
Coil Finger Ring
This ring was covered in a layer of thick soil. Cleaning the surface revealed a coil ring composed of a single copper alloy wire coiled into a ring (as the name suggests). The surface appears to be copper carbonates overlying the copper alloy core metal. This has the same texture as mentioned above and in the last post regarding the ‘powdery-textured’ surface. This is not suspected of being ‘bronze disease’.
The following thumbnails are linked to higher resolution photographs.
The next post will cover other copper alloy materials possibly identified as personal adornment that were recovered from the Cardiff Castle excavations.