Why Does Glass Take a Million Years to Decompose?

Glass is made by melting natural materials like sand at very high temperatures. This process creates a hard and stable material that does not easily react with water, air, or most chemicals. Unlike food, paper, or wood, glass cannot be broken down by bacteria or fungi. Instead, it slowly wears away through weathering. Wind, waves, and tiny pieces of sand can gradually grind glass into smaller fragments. However, those pieces are still glass, so they do not truly decompose. Scientists often say glass can last for up to one million years in a landfill because it changes so slowly. The exact time is difficult to measure, but it is much longer than the lifespan of most everyday materials. A practical takeaway is that glass can be recycled again and again without losing quality. Recycling helps save raw materials, reduces waste, and keeps glass out of landfills.