OSI Model - The Lower Layers The bottom four layers of the OSI model are often referred to as the lower layers: â¢ Layer-4 â Transport layer â¢ Layer-3 â Network layer â¢ Layer-2 â Data-Link layer â¢ Layer-1 â Physical layer Protocols that operate at these layers control the end-to-end transport of data
Ross-Simons' Agate Jewelry. Agate is a variety of chalcedony that comes in variety colors making it ideal for all kinds of jewelry designing. Blue agate is as expected, light blue. Moss agate is dark green, often with clear patches.Tree agate is green and white.gate: Stripes Earned by Nature. With its combination of earthiness and elegance, agate is one of the most unusual gemstones. There are many varieties of agate, including blue lace agate, moss agate, tree agate and petrified wood.
Agate /ËÃ¦É¡Ét/ is a cryptocrystalline variety of silica, chiefly chalcedony, characterised by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks. 1 Etymology and history.