Lava rocks belong to the igneous rock family and are created when lava cools down above the earth's surface and solidifies. The cooling lava is shaped into stones in all sizes, shapes and colors. Lava rocks can be found in areas with previous or present volcanic activity and have a porous consistency that retains heat and water naturally. They are versatile and can be used in a variety of procedures and products.
Gardeners and garden architects use lava rocks for decorative and water retaining purposes. The stones can be placed on pathways to give a colorful design effect, or used as border decorations. Smaller lava rocks are used as mulch to collect water and to avoid erosion. The porous material easily stores water on hot days and supplies roots with the liquid. Heat retained in the lava stones throughout the day will be released during the night, which gives the ground a balanced temperature level.
Grills and Barbecues
Lava rocks can either replace charcoal in traditional grills, or come as part of a gas barbecue appliance where the food is directly placed on heated slabs. Lava rocks retain heat and distribute it evenly over a cooking surface. The heat stored is homogeneous and remains the same in all parts of the barbecue. The porous surface of the stones or bricks absorbs fat, which can give grilled produce the aroma of wood. Gas barbecues with lava-stone slates are usually easier to clean because they have an even surface that simply can be wiped.
Lava rocks and stones are used in filtration systems for ponds and artificial wetlands where they clean the water. The porous material of the stones allows beneficial bacteria to grow easily and naturally. When water passes through the lava rocks, the bacteria remove the toxins from the liquid and purify it for further use in, for instance, groundwater replenishment and as garden watering resources.
Hot stone therapy is a traditional treatment that derives from the Pacific islands and uses warm, polished lava rocks to relieve stress and muscle pain. The stones are heated and placed on various parts of the body of a patient, usually in combination with aromatic scented oils. The lava rocks will release the heat slowly and allow the muscles to relax.
Lava rock is popular for use in deodorizer products that remove animal, mould and foot odors. The products usually consist of small sacks filled with the stones that easily can be placed in shoes, and on the offending places such as dog pillows, garden sheds or cellars. Small lava rock can be used in cat toilets. These products are a healthier alternative to sprays and detergents as they do not require the addition of pesticides and chemical fragrances, and can be used long term by regularly cleansing them with water and placing the stones in the sun for a few hours.
- The Franklin Institute: How Igneous Rock Is Formed
- James Madison University: Igneus Rocks
- Georgia Perimeter College: Igneous Rocks; Dr Pamela Gore, June 4, 2000
- Charcoal for Grill: Lava Rock for Barbecues
- Miami Valley Water Garden Society: Homemade Filter; Marilyn Miller
- American Massage Therapy Association: (Don't) Feel the Burn
- Lee Valley & Veritas: Volcanic Deodorizer
Based in the U.K., Petra Turnbull has been working as a journalist since 1989. Her articles on the film and book trades have been published in "Screen International," "Dagens Naringsliv," "Film Magasinet" and other Scandinavian newspapers and magazines. She now manages her own book shop. Turnbull holds degrees in law and economics from Goethe University, Germany and Oslo Business School in Norway.