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.
It is sometimes classified as a mineraloid. Though obsidian is usually dark in color similar to mafic rocks such as basalt, obsidian's composition is extremely felsic. Obsidian consists mainly of SiO 2 (silicon dioxide), usually 70% or more. Crystalline rocks with obsidian's composition include granite and rhyolite.t is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth. Obsidian is commonly found within the margins of rhyolitic lava flows known as obsidian flows, where the chemical composition (high silica content) induces a high viscosity and polymerization degree of the lava.