GeoCentral – Onyx Rock Mineral Specimen – Tumbled w Info Card

This shiny black onyx specimen measures approximately 1 inch to 1.25 inches in length.  Onyx is a cryptocrystalline variety of quartz.  It is composed of crystals so fine that they can only be seen with a microscope.  Solid black is probably the most well known color of onyx, but other colors range from brown to white and it is often striped, One of the many wonders of nature; your sample of Black Onyx has been tumbled to a smooth high sheen. It may differ in size, color and shape from the one pictured. It comes with a fact filled information sheet.

 

  Ages 6 and up