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
3%
1%
92%
3%
64
flagFinland
4%
0%
91%
4%
48
flagSpain
9%
2%
79%
9%
44
flagGermany
11%
3%
78%
5%
261
flagthe United Kingdom
11%
4%
77%
5%
563
flagCanada
9%
7%
76%
5%
52
flagthe United Arab Emirates
5%
5%
76%
11%
34
flagPoland
15%
4%
74%
5%
17741
flagthe Netherlands
13%
3%
73%
9%
83
flagFrance
18%
6%
72%
4%
50
flagthe United States
9%
4%
71%
13%
806
flagNorway
7%
2%
70%
17%
40
flagUnknown
20%
5%
68%
5%
74
flagAustralia
18%
1%
66%
13%
53
flagDenmark
20%
0%
64%
16%
25
flagRepublic of Ireland
15%
4%
63%
15%
63
flagthe Philippines
16%
2%
61%
16%
36
flagMalaysia
20%
4%
60%
16%
25
flagIndia
17%
8%
58%
12%
335
flagPakistan
34%
12%
25%
21%
32

Gender

men70%
women78%
ink
14%
12%
lead
7%
4%
cobalt
70%
78%
magnesium
7%
4%

Language versions

question
answers
results
flag
What was added to this glass to make it blue?
1878
66%

Details

Author: globalquiz.org
Illustration: Steven Depolo
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