Ontario introduced time-of-use (TOU) pricing to reflect the costs of producing electricity at different times of the day. There are three TOU periods: 1  Off-peak, when energy demand is low and less expensive sources of electricity is used. 2  Mid-peak, when the cost of energy and demand are moderate. 3  On-peak, when demand is highest and more expensive forms of electricity production are used.
Sheen Obsidian-this is a family of valued types which consists of sub-types categorized according to the effect or color displayed. Microscopic bubbles and/or crystals of Feldspar or Mica trapped in the Obsidian result in a chatoyant (irridescent) sheen when the stone is viewed from certain angles.heen Obsidian-this is a family of valued types which consists of sub-types categorized according to the effect or color displayed. Microscopic bubbles and/or crystals of Feldspar or Mica trapped in the Obsidian result in a chatoyant (irridescent) sheen when the stone is viewed from certain angles.
Obsidian: Volcanic Glass. When you buy a gem, you want to be sure that it is a natural stone and not glass. But there is one kind of natural gemstone that actually is glass. Obsidian is naturally occurring volcanic glass. It is formed when felsic lava extruded from a volcano cools without crystal growth. Obsidian has been known since prehistoric times, and has some fascinating properties as well as some important practical uses.