1 Brands: Tums, Caltrate, and most other brands.  Absorption: Calcium carbonate is alkaline based. It requires extra stomach acid for better absorption, so it is best taken right after meals or with a glass of acidic juice such as orange juice.
Tempered glass is one of two kinds of safety glass regularly used in applications in which standard glass could pose a potential danger. Tempered glass is four to five times stronger than standard glass and does not break into sharp shards when it fails. Tempered glass is manufactured through a process of extreme heating and rapid cooling, making it harder than normal glass.
Toughened glass can be made from annealed glass via a thermal tempering process. The glass is placed onto a roller table, taking it through a furnace that heats it well above its transition temperature of 564 Â°C (1,047 Â°F) to around 620 Â°C (1,148 Â°F).