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.
Types of Emeralds. By Amber Kelsey. The emerald gemstone is a variety of the beryl mineral. The beryl turns green due to chromium and vanadium impurities. There are several different types of emeralds, most of which are named for their country of origin. Columbian emeralds are mined in Columbia.