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. (geology). A jet-black volcanic glass, usually of rhyolitic composition, formed by rapid cooling of viscous lava; generally forms the upper parts of lava flows.Also known as hyalopsite; Iceland agate; mountain mahogany.bsidian polishes well. It is formed upon hardening of the viscous varieties of rhyolite lava or rhyodacite lava. Certain varieties of obsidian are used as decorative stones. In the Stone Age and Bronze Age, obsidian was used to make arrowheads, spearheads, knives, and scrapers.