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".
globalquiz.org
0
Correct this question
3
Very interesting!
reach: rather globalartbluebottleschemistrycolorsglasspainting

Answers by country

ink
lead
cobalt
magnesium
answers
flagSweden
5%
2%
86%
5%
37
flagthe Netherlands
9%
3%
81%
6%
33
flagAustria
15%
7%
76%
0%
26
flagGermany
9%
7%
75%
7%
247
flagSingapore
9%
0%
74%
16%
31
flagSwitzerland
4%
13%
73%
4%
23
flagUnknown
12%
3%
72%
11%
54
flagCanada
7%
9%
71%
11%
53
flagNigeria
10%
10%
71%
8%
49
flagthe United Kingdom
13%
6%
70%
7%
346
flagFrance
15%
7%
69%
7%
26
flagAustralia
15%
2%
67%
13%
108
flagGreece
0%
7%
67%
25%
28
flagPoland
21%
5%
66%
6%
23696
flagthe United States
11%
5%
65%
15%
960
flagMalaysia
14%
8%
60%
16%
48
flagRepublic of Ireland
19%
9%
54%
16%
31
flagthe Philippines
22%
5%
51%
19%
72
flagIndia
21%
10%
50%
15%
757
flagPakistan
32%
7%
37%
20%
80