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.
Flower Obsidian-a variety of Snowflake Obsidian in which the crystals have coloring (due to mineral staining or minerals present in the obsidian itself). See the Snowflake Obsidian topic below. Leopard Skin and Lizzard Skin-multi-colored, mottled types, usually reddish-brown, brown and black.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.
Even some of the black gemstones above â hematite, jet and obsidian in particular â are not categorically precious or semi-precious stones; but these black stones are used as ornaments. Other black rocks made into jewelry include amphibolites, lodestone, tektite and lava.ike white moonstones, the black gemstones hail from the group of minerals called feldspars, along with sunstone, oligoclase and andesine. The black semi-precious stones are not necessarily black entirely, but may be grey, interspersed in many cases with the beige and white of the more well-known moonstone.