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".
reach: rather globalartbluebottleschemistrycolorsglasspainting
Answers by country
ink
lead
cobalt
magnesium
answers

42

94

47

733

43

54

45

477

75

25918

140

61

1124

40

44

58

127

987

88

99