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%
58
flagItaly
2%
1%
92%
3%
85
flagthe United Arab Emirates
3%
3%
86%
6%
61
flagthe Netherlands
7%
3%
82%
6%
151
flagthe United Kingdom
10%
3%
79%
5%
800
flagGermany
12%
3%
78%
6%
337
flagSpain
9%
1%
78%
9%
51
flagGreece
9%
3%
78%
9%
32
flagFrance
15%
5%
75%
5%
60
flagCanada
11%
9%
74%
4%
62
flagPoland
16%
4%
73%
5%
25732
flagthe United States
9%
3%
72%
12%
913
flagSweden
18%
7%
71%
2%
38
flagNorway
10%
3%
70%
12%
55
flagAustralia
17%
3%
66%
12%
62
flagRepublic of Ireland
18%
6%
62%
13%
82
flagUnknown
28%
4%
59%
7%
1209
flagthe Philippines
20%
2%
57%
17%
45
flagIndia
19%
8%
56%
12%
387
flagPakistan
37%
9%
32%
16%
43

Gender

men67%
women78%
ink
19%
13%
lead
5%
4%
cobalt
67%
78%
magnesium
6%
4%

Language versions

question
answers
results
flag
What was added to this glass to make it blue?
2189
66%

Details

Author: globalquiz.org
Illustration: Steven Depolo
tools
Should this question be improved? Improve it.
Globalquiz questions are translated by users for other users. Translate this question.