Mineral Rummy
Introduction
Minerals can form beautiful gemstones or common salt crystals. What makes one mineral different from another? Play Mineral Rummy to learn about the chemical composition of common minerals.
Concepts
- Mineral classification
- Chemical composition
- Ionic compounds
Background
Minerals are natural compounds formed through geological processes. Minerals range in composition from pure elements and simple salts to very complex compounds with various forms. To be considered a mineral the following five criteria must be met.
A mineral must
- Be a solid.
- Occur naturally.
- Be inorganic (never alive).
- Have its atoms arranged in an orderly (crystalline) pattern
- Have a definite chemical composition.
More than 4,000 different minerals exist on Earth! Classifying these minerals helps geologists study them in a systematic way. One way to classify minerals is by their chemical composition. The minerals composed of pure elements are called native element minerals and are divided into native metals (e.g., copper and silver) and native nonmetals (e.g., sulfur). Most minerals, however, are compounds and may be classified by the anion (atom with a negative charge) in the compound. Some ions are single atoms and some are polyatomic ions—a charged group of two or more atoms covalently bonded. A polyatomic ion often found in minerals is the hydroxide ion, [OH] –. Magnesium hydroxide (Mg[OH] 2, known as brucite) is classified as a hydroxide mineral; however, the hydroxide ion may also be found in other mineral groups because it can form more complex mineral compounds. For example, malachite (copper carbonate hydroxide) is classified as a carbonate even though its chemical composition includes the hydroxide ion—Cu 2CO 3(OH) 2. The seven mineral groups included in the Mineral Rummy game are listed.
- Halides: Halides are salts that have a halogen anion—fluoride, chloride, bromide or iodide—bonded with a metal cation (positively charged atom). An example is halite (sodium chloride, NaCl)—common table salt.
- Oxides: These minerals are compounds of oxygen and a metal or metalloid. Corundum (aluminum oxide, Al2O3) is a common oxide used as an abrasive. Gemstone varieties of corundum include rubies and sapphires. Quartz—silicon dioxide—may be considered an oxide, but is usually classified as a silicate because of its chemical structure (see Silicates).
- Sulfides: All sulfide mineral compounds include the element sulfur as the sulfide anion. One abundant sulfide is galena (lead sulfide, PbS), the chief ore of lead.
- Carbonates: The carbonate polyatomic ion, [CO3]2–, combines with metal cations in this group of minerals. Identification of carbonates may include an acid test. If a dilute hydrochloric acid solution (HCl) is dripped onto a carbonate, a reaction takes place producing water and carbon dioxide gas, often with effervescence.
- Phosphates: This mineral group, composed of the phosphate polyatomic ion, [PO4]3–, includes minerals used in fertilizer as well as the beautiful turquoise gemstone (copper aluminum phosphate hydroxide).
- Silicates: These compounds of silicon and oxygen are the most abundant group of minerals. Silicates are complex, and the ratio of silicon atoms to oxygen atoms may vary. The tetrahedral shape of the silicate polyatomic ion, [SiO4]4–, is the basic chemical structure of all silicates. Quartz (SiO2) is usually included with the silicates since it is composed of silicon and oxygen and has a tetrahedral structure.
- Sulfates: The polyatomic sulfate ion, [SO4]2–, is the basis of this group of minerals. The most common sulfate is gypsum (calcium sulfate). One of gypsum’s primary uses is in the manufacture of sheetrock, also called drywall or wallboard. The walls in homes, offices and schools are usually at least partly constructed using gypsum board.
Experiment Overview
The purpose of this activity is to play a Mineral Rummy card game. Each player will collect ion cards that can be used to form specific minerals—see the Directions for Play PDF. The first player to use all of his or her cards to form minerals is the winner of Mineral Rummy!
Materials
Foam card holder, 1 per player List card, 1 per player Mineral cards, 16 Mineral Rummy deck of 55 ion cards Mineral Rummy Directions for Play
Prelab Questions
- Based on the five criteria listed in the Background section, is ice a mineral? Explain your reasoning.
- If classified according to the anion present, into what group would fluorite, CaF2, be placed?
- The mineral serpentine is magnesium silicate hydroxide, Mg3Si2O5(OH)4. Use the Background information to explain how this mineral should be classified.
Procedure
- Before playing Mineral Rummy, answer the Prelab Questions.
- Play one practice game as you read through all Mineral Rummy Directions for Play.
- Complete the Mineral Rummy Worksheet after playing the game.
|