In addition to being one of the most precious gemstones in the world, Agate also has industrial applications. Its color varies greatly and is determined by impurities. It is often white, milky white, or gray, but it can also have black, brown, green, or red spots, or in combination. Agate is an impure form of chalcedony, which in turn is a highly compacted form of quartz formed by microscopic crystals. Agate is often cut into thin slabs that are used as ornaments, or else it is cut into brooches and trinkets. As Agate absorbs liquids (it is porous), it can be easily dyed or colored to enhance the natural color and increase the commercial value of the gem. It is widely used as an abrasive to burnish and polish other materials of similar or lesser hardness and also in the manufacture of pestles and mortars, which are still used by chemists and pharmacists. The pestle, or pestle hand, is the instrument used to mix or grind substances; The mortar, also called pestle, is the vessel where the mixture or grinding is processed.


  • Title: Agate
  • Original Source: Tesouros da Terra - 2011, Editora Planeta DeAgostini - Revisão científica de: Prof. Dr. Rainer Schultz Guttler, do Instituto de Geociências (IGc), USP e Ideval Souza Costa, Geólogo do Museu de Ciências do IGc, USP.

Get the app

Explore museums and play with Art Transfer, Pocket Galleries, Art Selfie, and more


Google apps