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
flagFinland
3%
0%
93%
3%
59
flagSwitzerland
6%
1%
91%
0%
62
flagItaly
3%
2%
90%
4%
91
flagthe United Arab Emirates
2%
2%
88%
5%
68
flagthe Netherlands
7%
2%
83%
5%
180
flagthe United Kingdom
10%
3%
79%
5%
873
flagGermany
11%
3%
79%
6%
375
flagSpain
9%
1%
78%
9%
51
flagFrance
13%
4%
77%
4%
68
flagCanada
10%
10%
75%
4%
68
flagPoland
16%
4%
73%
5%
28603
flagthe United States
9%
3%
72%
13%
1017
flagNorway
11%
3%
71%
11%
59
flagSweden
22%
5%
70%
1%
58
flagAustralia
18%
2%
65%
13%
69
flagRepublic of Ireland
17%
6%
64%
12%
99
flagUnknown
28%
4%
59%
6%
1304
flagIndia
20%
8%
56%
12%
462
flagthe Philippines
17%
5%
55%
19%
56
flagPakistan
34%
8%
34%
18%
49

Gender

men68%
women78%
ink
19%
12%
lead
5%
3%
cobalt
68%
78%
magnesium
6%
4%

Language versions

question
answers
results
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What was added to this glass to make it blue?
2494
66%

Details

Author: globalquiz.org
Illustration: Steven Depolo
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