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.
#1 Agate Thin Slice. approximately 1/8 inch thick, 1.75 to 2.5 approximate width and 3.5 to 4 approximate length. Size and shapes of slices will vary. Slices may be ordered by color or assorted in 50 pc. packages only.