What was added to this glass to make it blue?

ink
lead
cobalt
magnesium
Powdered cobalt glass, called smalt, has been his­tor­i­cal­ly im­por­tant as a pigment in painting and pottery. It is colored to a deep powder blue hue using cobalt ions derived from cobalt oxide. Cobalt alu­mi­nate can be used in a similar way, and is now more common, often known as "cobalt blue".

Answers distribution

ink
lead
cobalt
magnesium
answers
flagItaly
0%
1%
94%
3%
55
flagFinland
5%
0%
89%
5%
39
flagCanada
10%
4%
80%
6%
50
flagthe United Kingdom
11%
4%
76%
6%
484
flagSpain
10%
2%
76%
10%
39
flagUU
20%
3%
76%
0%
30
flagGermany
14%
4%
75%
5%
217
flagPoland
15%
5%
73%
5%
16164
flagFrance
20%
4%
72%
2%
44
flagthe United Arab Emirates
9%
0%
72%
18%
22
flagthe United States
9%
4%
71%
13%
757
flagNorway
7%
2%
70%
17%
40
flagthe Netherlands
14%
4%
69%
11%
69
flagAustralia
20%
2%
66%
12%
50
flagRepublic of Ireland
18%
5%
60%
16%
55
flagthe Philippines
18%
3%
60%
15%
33
flagMalaysia
20%
4%
60%
16%
25
flagDenmark
20%
0%
60%
20%
20
flagIndia
18%
8%
57%
12%
306
flagPakistan
33%
13%
26%
20%
30

Gender

men69%
women78%
ink
15%
12%
lead
7%
5%
cobalt
69%
78%
magnesium
8%
4%

Language versions

question
answers
results
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What was added to this glass to make it blue?
1750
66%

Details

Author: globalquiz.org
Illustration: Steven Depolo
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