larah bowls are made of opal glass, which is a toughened opaque glass. it is not made of porcelain, stoneware, melamine or bone china.bone china crockery is made of bone ash of animals. larah crockery is made of glass and does not contain any bone ash.larah opalware is toughened glass and does not break or chip easily. our production process uses the highest quality raw materials and each individual piece is toughened by heat strengthening to increase its strength. this process ensures that the product can survive day to day handling without any breakage. yes, you can put boiling hot food in the bowls - it will neither crack nor leech any chemicals as the glass is unreactive (unlike melamine).over time, spices and oils can leave yellow stains on porcelain and other crockery - but not larah opalware! the glass will never yellow, and neither will it absorb any oil or haldi stains.yes, larah bowls are made of toughened microwavable glass, and can be used for heating food in the microwave. however, the lid is made of plastic and should not be used in the microwave.yes, larah crockery can be used in the dishwasher. they do not absorb haldi or oil stains and are easy to clean even by hand.