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Generally: for all eight tested
Copper:. In all except fake 3
Lead: only in fake 8
Potassium: only in fake 8
Manganese: In fake 2 and in the genuine 19th dynasty and genuine 4
Strontium: only in fakes 2 and 3 but not in fake 8 and in no genuine one
Vanadium: only in fake 2
Barium: only in fake 2.
However looking at these findings it is clear:
Mean value: 4.5
Calcium will be found in all faience the glazes.
It comes from the lime used to make up the mixture.
These figures resulted in a correct determination of false with 2.3% (number 2) but failed to spot the fakes numbers 3 and 8 with 16.4% and 0.6% respectively.
So calcium cannot be part of this database's algorithm.
Mean value: 0.98
Copper was deliberately added to create blue and green glazes.
These figures resulted in a correct determination of false with 1.2% (number 2) but failed to spot the fakes 3 and 8 with 0% and 1% respectively.
. So copper cannot be part of this database's algorithm
Widely found in Egyptian sands and some will derive from the plant ash used in much faience mixture.
Mean value: 0.38
Probably never added deliberated but will be often found in faience glazes up to 1%.
Iron was detected in both the correctly determined fake and in the two other define fakes "missed".
. So iron cannot be part of this database's algorithm
Very little tin is found in faience before the 18th dynasty.
Thereafter significant amounts are found; probably added to create a glossier glazes with more depth of colour.
Tin was only detected in two samples here , one definitely fake , (number 8) and one possibly genuine, (number 5) but both determined as genuine by these results.
The sample correctly determined as fake showed no tin, but then so did the definite fake number 3 show no tin, but was determined to be genuine.
. So tin cannot be part of this database's algorithm.
Egyptian sands have traces of manganese of around 0.1%
Manganese was deliberately added in rather varying amounts to create various colours in the glaze.
This element was found at 0.1% in the fake , number 2 correctly identified as fake.
However it was not found in the other definite fake, number 8, not so identified and was found in the genuine sample , number 4,
. So manganese cannot be part of this database's algorithm.
Cobalt is found in trace amount in faience of all periods.
It was added deliberately to create blue, violet and indigo colours but disappeared from use after the New Kingdom and reappeared in the Late Period.
Cobalt was not detected in any sample here.
We cannot say whether cobalt is part of this database's algorithm.
The lead content in faience glazes is a complex matter.
Although Jean-Jacques Fiechter says of fake ushabtis in his interesting book, "Egyptian Fakes" on page 193, "...the presence of lead in the paste provides irrefutable proof of modern manufacture" (no references given) , this is actually not quite accurate.
See Kaczmarczyk and Hedge's tables below:
Lead is suddenly found in yellow glazes in the 18th dynasty ( but not before) and then again in the Ptolemaic Period.
It is also found but in rather smaller amount in the late New Kingdom (19th and 20th dynasties) and the again in smaller amount in the 26th dynasty to the end of the Late Period, with another sudden peak occurring in the Ptolemaic.
The lead was from the yellow pigment lead antimonite.
Green and blue glazes:
Concentrations of lead in excess of 0.5% are very uncommonly found in green and to a lesser concentration in blue glazes before the sudden peak (and then equally sudden decline) in the Amarna Period and fewer than 10% of either these blue or green glazes have levels above 0.2% unless accompanied by significant amounts of tin and or antimony. Furthermore, both the 18th dynasty and Ptolemaic peaks of lead are found preponderantly with antimony concentration levels above a concentration of 0.2%
Any lead in the glazes was from the use of bronze scrap, which was the source of lead for these glazes. It was of course used deliberately and lead is never found in samples which are very low in antimony.
Lead was here detected only in fake number 8 at 2.7% and 1.4% , front and back respectively
This sample was determined as genuine.
. Lead cannot be part of this database's algorithm.
Zinc is found in Egyptian pigments only very late.
From the 18th dynasty lead was often added deliberately to specifically yield the yellow lead antimonite and copper- lead green.
Such glazes will also contain high percentages of zinc oxide but similar glazes of the Late Period and Ptolemaic period are relatively zinc free.
Zinc was found in the fake correctly determined such, number 2, (4.9%) .
It was also detected at 0.1% in number 8, the fake determined as genuine.
High levels of zinc might be part of this database's algorithm.
However it would then incorrectly determine as fake post 18th dynasty samples containing yellow lead antimonite and copper-lead green as these will also contain some zinc
Strontium as an impurity in Egyptian faience is rarely seen and never above 0.05%
Strontium was detected at 0.1% in the fake number 2 correctly so determined but was also found in the fake number 3 at 0.1% which was said to be genuine.
. Low levels of strontium cannot be part of this database's algorithm.
This element is found in Egyptian faience rather rarely and only at levels of around 0.06%.
Chromium was detected here only in fake number 8 at 0.1%which by these determinations was said to be genuine.
. Low levels of chromium cannot be part of this database's algorithm.
Barium and vanadium:
We have next to no data about vanadium in Egyptian sands or faience
Though Egyptian glass
Barium is found in trace amounts in Egyptian faience but only at levels of about 0.1%
Vanadium and barium was only here detected in the fake number 2, correctly identified as fake.
Barium and vanadium might be part of this databases algorithm.
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