Iron working debris - C Salter

Small slag prills and flows (smithing related)

5252, 621, 5.3,

Fragment of a slag flow or possibly a fragment of iron.

L 47 mm;W 45mm; T 29 mm; Wt 80.6

5208, 509, 7.1,

Inter-fuel dense slag flow

L 43 mm;W 27mm; T 20 mm; Wt 24.7

5292, 423, 9.2,

Slag flow. Inter-fuel 'flow' of highly magnetic slag.

L 35 mm;W 21mm; T 12 mm; Wt 12.4

5316, 229, 6.7,

Small drip-like flow.

L 37 mm;W 29mm; T 16 mm; Wt 12.4

5316, 229, 6.7,

Fragment of inter-fuel slag formation.

L 25 mm;W 20mm; T 18 mm; Wt 6.6

5302, 730, 6.7,

Small irregular 'flow'.

L 27 mm;W 18mm; T 15 mm; Wt 7.9

5302, 730, 6.7,

Irregular prill.

L 24 mm;W 20mm; T 16 mm; Wt 9.8

5302, 730, 6.7,

Small irregular 'flow'.

L 30 mm;W 16mm; T 13 mm; Wt 5.4

5003, 150, 12.4,

Small flow, almost planar fragment of inter-fuel slag.

L 44 mm;W 24mm; T 12 mm; Wt 18.7

5003, 150, 12.4,

Fragment of inter-fuel or F_S_1 type slag.

L 27 mm;W 16mm; T 14 mm; Wt 8.9

5003, 150, 12.4,

Probably a fragment of intra-fuel slag.

L 38 mm;W 23mm; T 22 mm; Wt 17.1

5003, 150, 12.4,

Slag:- An irregular viscous single flow. Probably broken from a more complex furnace form.

L 58 mm;W 21mm; T 19 mm; Wt 19.7

5357, 248, 6.2,

Fragment of a part of a slag 'flow'.

L 32 mm;W 22mm; T 15 mm; Wt 15.3

5243, 248, 6.2,

Irregular 'flow' type structure, but highly magnetic.

L 36 mm;W 27mm; T 20 mm; Wt 20.5

5354, 554, 6.3,

Irregular fragment of a 'flow'.

L 32 mm;W 29mm; T 16 mm; Wt 11.5

, 129, 9.2,

Two small inter-fuel 'drip' type forms.

Wt 5.8

, 150, 12.4,

Inter-fuel flows and prills, 9 fragments.

Wt 37.3

, 77, 12.4,

8 slag prills or minor outflows broken from a larger form

Wt 13.4

, 77, 12.4,

Three large (over 4 mm in diameter) slag spheres

Wt 1.6

, 77, 12.4,

A series of 12 minor slag flows and prill that could easily have come from the smithing hearth bottom.

Wt 25.0

Furnace slag flows and prills

5003, 150, 12.4,

Furnace slag type 1. Large piece of slag forming around charcoal fuel (up to 30 mm). Small portion showing flattening against furnace wall or other slag (former more likely as surface vertical).

L 67 mm;W 61mm; T 64 mm; Wt 208.0

5003, 150, 12.4,

Piece of furnace slag. Three slag lobes rested against furnace wall as white furnace lining retained. Sulphur coloured corrosion products present, although less noticeably than in the rest of these F_S_1 type slags. Common in all 5003 slag.

L 51 mm;W 41mm; T 40 mm; Wt 46.8

5003, 150, 12.4,

Piece of furnace slag. No contact with furnace wall indicated.

L 69 mm;W 43mm; T 33 mm; Wt 87.8

5003, 150, 12.4,

Probably from the upper part of the furnace as shows trend towards

F_S_2 form. One side flattened again cold surface (furnace wall?), possibly a second surface (not well defined) at acute angle to it (70). Some white furnace lining on this surface.

L 69 mm;W 53mm; T 52 mm; Wt 164.0

5003, 150, 12.4,

Piece of lobate flow furnace slag with small area of furnace wall flattening.

L 79 mm;W 73mm; T 52 mm; Wt 238.0

5003, 150, 12.4,

Furnace slag Form is cross between F_S_1 and the more cindery F_S_2, enclosing fuel (charcoal) An area of flattening against stone or ore.

L 62 mm;W 62mm; T 33 mm; Wt 112.0

5003, 150, 12.4,

Mass of cindery slag enclosing fuel (charcoal) particles (5-10mm) Some of the charcoal structure preserved by iron mineralization.

L 93 mm;W 44mm; T 38 mm; Wt 114.0

5003, 150, 12.4,

Mass of cindery slag with some regions of more rounded forms in the lower parts. Small fuel particle size.

L 62 mm;W 59mm; T 32 mm; Wt 110.0

5003, 150, 12.4,

Cindery furnace slag

L 80 mm;W 53mm; T 31 mm; Wt 124.0

5003, 150, 12.4,

Interface between cindery and rounded flow forms of furnace slag.

L 48 mm;W 48mm; T 35 mm; Wt 108.0

5003, 150, 12.4,

Fragment of run-type furnace slag.

L 47 mm;W 30mm; T 21 mm; Wt 33.7

5003, 150, 12.4

Small fragments (15) probably from F_S_1 type material.

5003, 150, 12.4

Intra-fuel slag flow (three dimensional).

L 42 mm;W 31mm; T 28 mm; Wt 18.3

5003, 150, 12.4,

Fragment of intra-fuel slag flow.

L 58 mm;W 34mm; T 18 mm; Wt 29.5

, 77, 12.4,

A series of drips and prills have fused together to form a roughly rectangular lump of slag, but the process has not gone far enough to produce the classic smithing hearth forms.

L 47 mm;W 43mm; T 25 mm; Wt 55.8

, 76, 12.4,

Six slag drips and prills.

Wt 21.2

Slag - smithing hearth bottoms and sub-tuyere slag plates

5307, 745, 7.2,

The other half of 5317 Bowl-shaped plano convex smithing hearth bottom. Dimensions given here are those of the two halves combined.

L 88 mm;W 66mm; T 23 mm; Wt 126.0

5360, 314, 10.1,

Plano-convex smithing hearth bottom, surfaces poorly preserved. Breaks on two sides at 90 degrees Thick central portion with low porosity.

L 76 mm;W 69mm; T 39 mm; Wt 304.0

5309, 549, 7.2,

Small flat slag flow with evidence of flow channel voids. The sample was strongly magnetic in the regions. It was more cindery surface.

L 40 mm;W 37mm; T 19 mm; Wt 41.9

5247, 252, 5.2,

A small sub-tuyere smithing slag formation, (proto-type 4), with a small slag plate (type 3) forming above, but fused to a smaller irregular and more cindery slag form (type 2).

L 55 mm;W 44mm; T 29 mm; Wt 72.8

5315, 708, 6.7,

Fragment of 'smithing' hearth bottom About 25% of whole bottom. Moderately magnetic, with manganous oxide sheen on fracture surfaces Similar in many respects to 5270 although less magnetic.

L 45 mm;W 36mm; T 27 mm; Wt 95.8

5267, 639, 6.2,

Typical irregular sub-tuyere slag plate Moderately magnetic.

L 47 mm;W 40mm; T 22 mm; Wt 66.8

5317, 549, 7.2,

Well developed smithing hearth bottom of very dense slag. The upper surface highly magnetic, the low surface less so. Top 6-7 mm clear of porosity, however, below that normal smithing hearth bottom type pores distribution.

L 72 mm;W 50mm; T 25 mm; Wt 164.0

5272, 421, 9.2,

Smithing hearth bottom. The upper more irregular than 5317 and porosity evenly distributed. The lower surface more magnetic than upper. Virtually complete.

L 78 mm;W 66mm; T 34 mm; Wt 310.0

5325, 0, ,

Tongue-shaped, relatively thick, plano-convex smithing hearth bottom, highly magnetic planar upper surface. Entirely covered in thick hard iron oxide layer.

L 102 mm;W 68mm; T 35 mm; Wt 350.0

5269, , ,

Thin irregular plate-shaped smithing hearth bottom. Hammer-scale trapped in the surrounding layer of soft brown iron mineralization Moderately to highly magnetic

L 77 mm;W 73mm; T 21 mm; Wt 142.0

5240, 578, 7.2,

Fragment of dense planar smithing hearth bottom, probably 50% of the whole. Unusually dense, and strongly magnetic. One area of small prills running together to form the hearth bottom, whereas, other area are of well consolidate (even crystalline) slag.

L 57 mm;W 55mm; T 25 mm; Wt 126.0

5019, 50, 12.1,

Double smithing hearth bottom. The upper part a semi-circular curve of dense slag formed on top of a full pudding-shaped hearth bottom. The upper part strongly magnetic, the lower less so.

L 123 mm;W 113mm; T 88 mm; Wt 1250

5004, 96, 6.1,

Very small sub-tuyere formation with fuel mark.

L 40 mm;W 31mm; T 22 mm; Wt 41.9

5004, 96, 6.1,

Sub-tuyere slag formation with fuel marks.

L 40 mm;W 31mm; T 22 mm; Wt 20.9

5028, 130, 9.3,

Fragment of dense slag with large gas voids on upper part. Probably part of sub-tuyere slag plate.

L 42 mm;W 31mm; T 20 mm; Wt 27.2

5028, 130, 9.3,

Part of a bowl-shaped smithing hearth bottom. Probably 45% of the whole.

L 56 mm;W 46mm; T 18 mm; Wt 110.0

5261, 421B, 9.2,

Roughly triangular smithing hearth slag plate with top surface missing due to present of gas voids. Patchily moderately magnetic

L 65 mm;W 47mm; T 20 mm; Wt 57.0

5316, 229, 6.7,

Irregular flow or small sub-tuyere slag formation, with hammer scale on surface

L 38 mm;W 26mm; T 22 mm; Wt 30.7

5302, 730, 6.7,

Irregular type 4 (/3) smithing hearth

L 71 mm;W 51mm; T 25 mm; Wt 98.4

5067, 229, 6.7,

Smithing hearth bottom. Badly coated with hard-pan type material preserving fuel (charcoal + coal?) and some hammer-scale.

L 90 mm;W 76mm; T 31 mm; Wt 262.0

5003, 150, 12.4,

A fragment of slag with the form of very irregular sub-tuyere smithing hearth plate-shaped bottom. Although, there appears to be some sub-hedral surface crystal growth, and very little normal slag/atmosphere interface.

L 48 mm;W 34mm; T 18 mm; Wt 38.2

, 96, 6.1,

Fragment of the core of a smithing hearth bottom.

L 39 mm;W 24mm; T 20 mm; Wt 27.5

5357, 248, 6.2,

Irregular slag 'flow' beginning to form a more planar structure.

L 52 mm;W 47mm; T 14 mm; Wt 42.3

5232, 313, 10.1,

About half of a small rather deep smithing hearth bottom.

L 53 mm;W 43mm; T 40 mm; Wt 14.4

5197, 239, 6.1,

About half or a small sub-tuyere slag plate, but with pale pinkish-yellow corrosion layer.

L 37 mm;W 36mm; T 22 mm; Wt 31.7

, 129, 9.2,

Fragment of well crystallized sub-tuyere slag plate.

L 36 mm;W 22mm; T 15 mm; Wt 23.5

, 150, 12.4,

Irregular sub-tuyere slag plate-cum-full smithing hearth bottom in form. However, the hearth temperature low as surface of sinter rather than melt form. Slag removed from hearth while plastic (evidence of tearing).

Wt 404.0

, 77, 12.4,

Smithing hearth bottom consisting mainly of partially sintered iron oxide and metal possibly derived from a bloom, or by the accidental oxidization of iron during smithing. On one side the temperature was high enough, or there was sufficient fluxing element for true slag to start forming.

L 92 mm;W 90mm; T 35 mm; Wt 304.0

Slag associated with possible smelting activity (sinter form)

5003, 150, 12.4,

Slag:- fragment of unclassified dense slag with charcoal marks and

possible flattening against cold surface.

L 41 mm;W 33mm; T 25 mm; Wt 40.8

5003, 150, 12.4,

Fragment of some larger form, probably the intermediate slag drain zone of a furnace slag.

L 37 mm;W 34mm; T 26 mm; Wt 41.2

5003, 150, 12.4,

Slag fragment. No obvious form. However, it does seem to be similar to some of the cindery furnace slags.

L 37 mm;W 35mm; T 17 mm; Wt 21.6

5003, 150, 12.4,

Roughly semi-circular fragment of sinter type slag covered in yellow secondary iron minerals. Could be a sub-tuyere plate but the surfaces are not right for that.

L 59 mm;W 40mm; T 25 mm; Wt 57.4

5003, 150, 12.4,

Slag of indefinite form but rather dense, suggesting the presence of metallic iron.

L 34 mm;W 32mm; T 18 mm; Wt 31.7

5003, 150, 12.4,

Slag, high density magnetic.

L 30 mm;W 26mm; T 19 mm; Wt 21.8

5003, 150, 12.4,

A very irregular planar form with slag forming between a cooler region (lining) and fuel particles. The flow forms are tighter and more viscous than those of F_S_1

L 52 mm;W 35mm; T 19 mm; Wt 30.8

5003, 150, 12.4,

An irregular fragment of semi-planar slag with sinter type upper surface and some lobate slag flows on lower. However, looks rather like hard-panned forge floor.

L 73 mm;W 43mm; T 25 mm; Wt 35.9

5003, 150, 12.4,

Planar fragment of sinter type slag with a region of more normal slag. (Again it is not clear whether this is a slag drain region, or an iron sinter).

L 51 mm;W 44mm; T 16 mm; Wt 41.4

5003, 150, 12.4,

An irregular fragment of semi-planar slag with sinter type surface.

L 73 mm;W 41mm; T 24 mm; Wt 54.4

5003, 150, 12.4,

Highly magnetic sintered looking slag. It appears that a thick sheet of the 'slag' has been rolled up (or picked up by tongs whilst still soft).

L 113 mm;W 75mm; T 41 mm; Wt 302.0

5003, 150, 12.4,

Mass of sinter type slag with a very irregular type 4 form.

L 76 mm;W 54mm; T 32 mm; Wt 154.0

5003, 150, 12.4,

18 fragments of low-moderate density sinter slag forms

Wt 152.0

5003, 150, 12.4,

Slag fragment. A fragment of micro-crystalline surface covered in dark brown rust. Possibly an area from which more liquid slag has drained, or possibly an area of iron sinter formation.

L 39 mm;W 25mm; T 17 mm; Wt 15.8

5003, 150, 12.4,

A larger fragment of the slag-drain or iron sinter type material

L 40 mm;W 38mm; T 24 mm; Wt 50.2

5003, 150, 12.4,

Small fragment of dense sinter type slag.

L 33 mm;W 31mm; T 18 mm; Wt 21.6

5003, 150, 12.4,

Fragment of sinter slag with layer of yellow iron secondary mineralization on one side.

L 50 mm;W 46mm; T 25 mm; Wt 51.0

Slag spheres (SS) and hammer scale (HS) by context

(only those contexts with significant amounts given)

Context 16 Block 7.5 Type SS Wt .3 No 6

Context 48 Block 12.2 Type SS Wt 0.0 No 20

Context 58 Block 12.1 Type SS Wt .1 No 5

Context 76 Block 12.4 Type SS Wt 1.1 No 5

Context 201 Block 1.0 Type SS Wt 2.3 No 9

Context 226 Block 6.7 Type SS Wt 1.9 No 13

Context 261 Block 7.5 Type SS Wt .2 No 15

Context 402 Block 9.2 Type SS Wt .1 No 10

Context 404 Block 9.3 Type HS Wt 1.3 No 1

Context 421 Block 9.2 Type SS Wt 3.7 No 18

Context 543 Block 7.2 Type HS Wt 31.5 No 800

Context 543 Block 7.2 Type SS Wt .2 No 8

Context 549 Block 7.2 Type SS Wt 1.4 No 16

Context 563 Block 7.2 Type SS Wt .1 No 6

Context 575 Block 6.3 Type SS Wt 1.6 No 15

Context 578 Block 7.2 Type HS Wt 198.0 No 3000

Context 578 Block 7.2 Type HS Wt 13.1 No 14

Context 578 Block 7.2 Type SS Wt 1.6 No 16

Context 581 Block 5.5 Type SS Wt .3 No 13

Context 583 Block 7.2 Type SS Wt .5 No 8

Context 593 Block 6.2 Type HS Wt .2 No 10

Context 608 Block 7.2 Type HS Wt 13.4 No 100

Context 608 Block 7.2 Type SS Wt 1.3 No 6

Context 616 Block 7.3 Type SS Wt .1 No 5

Context 679 Block 7.7 Type SS Wt 1.6 No 7

Context 680 Block 7.5 Type SS Wt 1.9 No 30

Context 686 Block 7.2 Type SS Wt .1 No 5

Context 691 Block 6.6 Type SS Wt .4 No 8

Context 732 Block 1.0 Type HS Wt 7.4 No 1

Context 749 Block 7.5 Type SS Wt .1 No 10

Context 773 Block 7.5 Type SS Wt 6.4 No 30

Hearth lining

5375, 252, 5.2,

Hearth Lining. Vitrified hearth lining, with vitrification layer 8-10 mm thick. Clay micaceous, and partially dissolved crystals of unidentified minerals (quartz or possibly feldspars).

L 34 mm;W 28mm; T mm; Wt 15.2

5394, 708, 6.7,

Two fragments of red fired clay. The larger with a thin blackened layer, possibly vitrification, although could just be reduced firing or sooting. No real evidence of these fragments being mould fragments.

Wt 13.1

5384, 34, 7.5,

Furnace lining clay partially vitrified. There are two depressions into the surface. Flat non-fired surface suggesting that this was a repair to a brick lined hearth! Clay appears rather refractory! Wt 19.5

5403, 294, 7.1,

Thick piece of fired clay, non obvious form other than one apparently slip covered face, (possibly the fired face).

Wt 64.0

5292, 423, 9.2,

A flow of slag and black glassy slag-lining vitrification product over pink-grey furnace lining. One area highly magnetic whereas rest only moderately

L 67 mm;W 57mm; T 48 mm; Wt 196.0

5003, 150, 12.4,

Slag and furnace lining. A layer of dense slag approximately 20 mm thick over possible furnace lining. (The lining material appears to be a micaceous schist, although the bed-rock is described as limestone.

L 54 mm;W 49mm; T 31 mm; Wt 102.0

5003, 150, 12.4,

A fragment of material identical to that seen on 201. Although, initially it would appear to have a low iron content it is highly magnetic!

L 19 mm;W 17mm; T 11 mm; Wt 2.1

, 150, 12.4,

Hearth lining, 10 fragments.

Wt 28.0

, 402, 9.2,

Hearth lining, 3 fragments.

Wt 1.6

, 77, 12.4,

Fragments of fired hearth lining, 5 fragments

Wt 12.2

, 76, 12.4,

Two fragments of furnace lining, fired under reducing conditions.

Vitrification layer 4-6 mm thick.

Wt 78.0

Burnt clay - possibly mould fragments

5392, 284, 7.1,

Burnt clay. Body & firing compatible with being mould, but no surfaces or burning characteristic of mould fragments visible.

Wt 7.8

5400, 517, 4.3,

Probably mould fragment, at least one small spec of copper corrosion product visible, but not strongly attached (contamination ?).

Wt 3.1

5102, 549, 7.2,

Probably a mould fragment, there are possible spills of slag on surfaces, worth checking

Wt 23.0

Non-specific burnt clay

5412, 279, 7.1,

Burnt clay. Not mould fragment as no sign of characteristic surfaces or localized heating.

Wt 4.8

5390, 509, 7.1,

Burnt clay. Not mould fragment as no sign of characteristic surfaces or localized heating.

Wt 5.5

5401, , ,

Burnt clay. Not mould fragment as no sign of characteristic surfaces or localized heating.

Wt 12.8

5396, 726, 7.6,

Burnt clay, 4 fragments. Not mould fragments as no sign of characteristic surfaces or localized heating.

Wt 27.2

5393, 280, 7.1,

Burnt clay 3 fragments. Not mould fragment as no sign of characteristic surfaces or localized heating.

Wt 5.6

5347, 564, 5.2,

Abraded burnt clay.

Wt 0.7

5383, 34, 7.5,

Shell of low fired or mineralized clayey soil on one side, the other layer of black organic material (grass or reed stems rather that wood) with possible traces of copper minerals.

Wt 3.0

, 13, 7.7,

Fire hardened yellow clay (or hard-pan) around similar coloured piece of schist.

Wt 7.8

Tuyere

5388, , ,

Fragment of furnace lining from around tuyere (air blowing hole). Tuyere diameter about 20 mm (only 15% of circumference present). this rather small for iron smelting furnace. The presence of copper prills within the glaze confirms that the furnace this tuyere came from was used for non-ferrous metallurgy, although this does not exclude its possible use for iron smithing.

Wt 12.2

5408, 239, 6.1,

Not a mould fragment. A lump of grey clay with sand particles. A shallow broad groove on one side. Sand quartz, mica schist, and other darker rocks. Comparable with crucible Campbell type 4?

Wt 130.0

Copper alloy working debris

Metallic copper

, 422, 9.3,

Copper alloy prill. (Approximately 10% tin bronze)

Wt .2

, 680, 7.5,

Copper alloy point ( 8% tin, 2% Zinc alloy)

Wt .1

Crucibles

1399, 607, 6.2,

Campbell Vessel 1. Red glazed exterior with a number of spots of green copper corrosion products, some of these were sampled. Proved to be of corroded bronze, only the tin-rich epsilon remained uncorroded.

Wt 31.1

1399, 607, 6.2,

Campbell vessel 1. Typical crucible fragment.

Wt 8.0

5387, 668, 6.4,

Rim fragment of Campbell vessel 1. Usual red glaze externally, with incipient slagging internally.

Wt 3.2

5404, 313, 10.1,

White fabric pudding bowl shaped crucible probably semi-triangular, about 32-35 mm deep (externally). Striations internal & externally associated with manufacture. Smaller than vessel 1 similar to vessel 2.

Wt 10.2

5405, 700, 6.4,

Campbell Vessel 1. A larger crucible type with red and black glazes on exterior, and a few regions of glaze in the interior.

Wt 13.2

5405, 700, 6.4,

Rim fragment of Campbell vessel 1, with usual red and black glazes. One possible metal prill.

Wt 6.6

5406, 707, 6.4,

Campbell vessel 2. Glaze covered rim fragment.

Wt 2.7

5406, 707, 6.4,

Campbell vessel 2. Small rim fragment with area of thick black glaze, sampled. This crucible had been used to melt and probably refine silver and may be gold. As is indicated by the presence of silver bromide and iodide enclosing a metallic phase with up to 10 weight % gold.

Wt 2.2

5407, 598, 4.2,

Campbell vessel 1. Regions of black glaze on the external surfaces.

Wt 4.9

5012, 50, 12.1,

Campbell Vessel 4. Small bag-shaped crucible but of a very much courser fabric, than the rest from the site. No metal prills or glaze visible on inside, although the outside black glaze indicates that it has been used.

Wt 23.0

5413, 652, 6.2,

Campbell vessel 1. Glazed both sides, no metal prills.

Wt 1.5

5414, 59, 12.3,

Campbell vessel 3. Small fragment of crucible with red and brown glazes but no obvious metal trapped. Sampled, analysis points to it having been used for the melting of bronze. The surface layer has tin-rich prills, whereas, deeper into the glaze the prills are of a more 'normal' bronze composition. There was evidence of this crucible having been used for gold or silver alloys.

Wt 1.2