Tis the season for decorating with pastels, and shades of light blue bring a cool, calming quality evocative of summer skies ...

Sky-blue material is produced in the Bai Son and Lung Thin areas, as well as near Bai Gau (Senoble, 2010). In Luc Yen, rough spinel crystals occur in dolomitic marble with calcite, phlogopite, humite, ...