The most important thing to learn about the OSI model is what it really represents. Pretend you're an operating system on a network. Your network card, operating at layers 1 and 2, will notify you when there's data available. The driver handles the shedding of the layer 2 frame, which reveals a bright, shiny layer 3 packet inside (hopefully).
Used with permission. Agate is a variety of chalcedony, a cryptocrystalline form of quartz. Translucency, patterns of color, or moss-like inclusions may distinguish this stone from other forms of chalcedony. Agates can show a wide variety of vivid, multiple colors.
Physical Properties of Agate. Agate colors and patterns can vary a great deal. Some are white or grey, while others are pale blue, orange, red, black, or even banded with more than one color present. They are translucent, with some being nearly opaque and others being relatively easy to see through.