PPT-GEMSTONES DEFINITION MINERALS that are cut

RARE valuable Usually above 7 on hardness scale Gold Pure gold is malleable heavy and expensive Gold in jewelry is an alloy mix of metals K of gold 24K 100 gold 14K The 5 Cs. . by Head of trade restrictions, . currency and export control . Sergey . Shklyaev. Precious metals and gemstones. 1. Federal law No 41-FZ dated March 26,. 1998 . on precious metals and gemstones. Gemstones. By Cara . Chae. -Banks. And. Ian . Gevanthor. Distiguishing. Characteristics. Color: Yellowish gray (often mistaken for gold). Class: Sulfides . Luster: Metallic. Cleavage: Very distinct. Streak: Greenish-black. . Mineral. . Resources. (pages. . 80–85). Key. Concept:. . Minerals are the . source. of gemstones,. . metals,. . and a . variety. of materials used to make . many. . products.. A. . g. emstone. naturally occurring, . inorganic solid . with a specific chemical composition . a definite crystalline structure. Minerals can form from the cooling of magma which is the molten material found beneath Earth’s surface as magma rises closer to the surface the molten compounds no longer move freely and they begin to interact chemically to form minerals. All rocks are made up of 2 or more of these minerals. . Minerals are not rocks!. Silicon and oxygen are the most abundant elements in the crust and in minerals. Oxygen is the most abundant element in minerals. Tips on Buying Gemstones Online In this section you will find prices for glass gemstones in all the basic shapes like Round, Oval, Pear, Octagon, Square, Heart and Marquise. We can supply glass stones in about 200 colors. If you are looking for a cheap gemstone (even cheaper than CZ and Synthetic stones) then you should go for these Glass gemstones. All You Need To Know About Different Types of Gemstones Buying a colorful gemstone is the supreme fashion accessory. Starting from the ruby, emerald, and violet gemstones to the few known as spinel, kunzite excludes synthetic minerals. inorganic. non living processes form them. chemically specific. has a unique proportion of elements. crystalline solid. atoms are arranged in specific 3-D patterns. Definition:. 1. What is Petrology?-. Study of Rocks. 2. What Study?-. Source and Processes. 3. How to Study?-. Field Relations, Field characteristics, Mineralogical (what are the minerals?), . Petrographical. ( . Sandstone uranium deposits occur in carbon and/or . pyrite-bearing fluvial . (less commonly marine), . arkosic. , medium to . coarse-grained sandstones . that contain, are interbedded with, and are bounded by . Geo 281: geology for engineers. Geology and Geophysics Department. King Saud University. Minerals: Building. Blocks of Rocks. We begin our discussion of Earth . materials with . an overview of . mineralogy (mineral = mineral and Logy=Study) because . Background Information!. The Earth’s crust is made of mostly rocks and soil.. The rocks are made of different combinations of . minerals.. Minerals . are made of . elements. . (. Remember an element .