418 (15)

Metallurgical Analysis ofthe Dress Accessories

somewhal purer (aboul 55% gold) and had been mainly debased with silver although it still con-tained about 15% copper. Both nos. 1612 and 1613 were in two parts and in both cases the analytical results were consistent with the two parts being of the same composition.

Number 1610 consists of three parts; the hoop, bezel and collet. The hoop is significantly purer (about 75%) gold than either the bezel or collet. The analyses of the bezel and the collet were not significantly different. from each other (55-60% gold, debased with about equal amounts of copper and silver).

Two other objects, gold fmger ring no. 1614 and the coating of silver-gilt rnirror case no. 1718, were analysed qualitatively by XRF. Comparison with similar analyses of the gold finger rings that were also analysed by SEM suggest that the gold of both was relatively fine. The metal of the former is probably about 75-85% gold, whilst the coating on the latter is almost pure gold.

Nonę of the silver objects was analysed quanti-391

tatively but the seven silver objects analysed by XRF were of varying fineness. Comparison with silver objects of known composition havc allowed some estimate of fineness to be attached to the silver dress accessories analysed. Three objects were relatively pure silver (ie over 90% silver): probable buckie no. 211, brooch no. 1334 and the pin of brooch no. 1337. Dress pin ąo. 1488 is heavily debased, with a silver eon tent of about 50%, whilst the pin of brooch no. 1339 and the frame of no. 1337 were even less fine, with silver contents of about 40%. In the debased silver objects the main other element present was copper, though they also contained smali levels of zinc, which suggests the silver was debased by adding brass to the metal.

Gold and silver were also used to coat the surface of a smali number of objects, mostly brooches, buckles and strap-ends. Ninę objects coated with precious metals were analysed; two of these were clearly mercury-gilded, but mer-cury was not definitely detected in the other

Variations through time

analyses

19 16

20 112

15

215

72

An attempt was madę to identify possible changes in alloy usage from the mid twelfth century to the mid fifteerith century. The number of analyses for each ceramic phase and the metals represented are as

follows: ceramic	no. of	copper brass		gunmetal		bronze	lead	tin	pewter	gold	silver
phase 6 (1150-1200)	analyses 24	9	4	5		1			3		1
7 (1200-1230)	26	5	3	4		4	-	5	4	-	1
8 (1230-1260)	33	3	11	4		2	-	2	10	-	-
9 (1270-1350)	147	13	55	40		14	-	8	12	-	-
10 (1330-1380)	16	-	8	3		1	-	3	1	-	-
10/11(1330-1400)	4	-	2	1		-	-	-	-	1	-
11 (1350-1400)	275	15	125	46		29	2	22	19	3	5
12 (1400-1450)	113	3	51	12		6	-	27	9	-	-
unstratified	26	1	7	1		2	1	5	5	1	-
unphased	9	2	3	1		-	-	1	1	1	-
total	649	51	269	117		59	3	73	64	6	7
Element ratios	for the copper		alloys analysed		ceramic		no. of	proportion of		copper alloys

from each ceramic phase are shown in figs 263 to 269 plotted on ternary diagrams. The proportion of the individual copper alloys in each phase is shown at the right (C = copper, G = gunmetal, Ae = bronze):

phase

6

7

8 9

10

11

12