Geosc 001 Spring 2006 Lab 2Mineral IdentificationYour Geosc 001 instructors, Eliza and Dave, along with your Geosc 001 TAs, Emily andBrett, were invited to President Spanier’s house to watch the Orange Bowl. Each of thembrought a collection of the same five minerals so they could all compare their specimenswith Pres ident Spanier’s specimens after the game. During regulation (before the threeovertimes), another jealous party-goer who wished he were a geologist so he could own coolmineral samples stole one mineral from each of their collections, including from PresidentSpanier’s collection. He then hid the minerals somewhere in the President’s house. Eliza ismissing her quartz sample, but she still has her potassium feldspar, magnetite, biotite, andcalcite. Each of the others is also missing one mineral specimen. You have been given a boxthat contains samples of all five minerals. Your job is to identify each mineral in the boxand, using the clues below, determine which mineral was stolen from which person, whenduring the game it was stolen, and where in the house it was hidden.1. Neither Eliza nor Emily was missing a mineral during the first quarter of the game.2. The mineral that reacts to a weak solution of hydrochloric acid (see page 3) wasnot found in the bedroom or the bathroom.3. Emily and Eliza looked in the b edroom and bathroom with no luck after Emily found hermineral was missing during halftime.4. The mineral with a metallic luster (see page 3) went missing during the third quarter.5. The person missing the mineral that makes a dark streak on the streak plate (seepage 4) and the person whose mineral went missing during the first quarter both told Brettthat they were worried about Florida State’s potential for making big plays during puntreturns.6. Brett was glad no one stole his mineral that has the unique property of doublerefraction (see page 4) or his mineral with the “platy” crystal habit (see page 5) buthe was shocked to discover his mineral missing early in the game.7. The person missing the mineral with one direction of cleavage (see page 5) wasrelieved when someone who had to leave the party early found it in the coat closet after thefirst quarter.8. It was during the fourth quarter that Eliza found her mineral whose hardness is ≈ 7on the Mohs scale (see page 5) missing. She checked everywhere, even the kitchen, but itwasn’t until after the 3rd overtime that anyone looked in the wine cellar and found it there.9. The person missing the magnetic mineral (see page 7) did not find it in the bathroom.10. Graham Spanier was relieved when he tripped over his missing mineral in the bedroom.Which mineral in your box is which?1.2.3.4.5.1Geosc 001 Spring 2006 Lab 2quartz kspar magnetite biotite calcite 1st 2nd half 3rd 4th bedroom bath closet kitchen cellarElizaDaveEmilyBrettGrahambedroombathroomclosetkitchencellar1st2ndhalf3rd4thSumming UpPerson Mineral When Where2Geosc 001 Spring 2006 Lab 2Dissolution of MineralsOnly a few minerals, like halite, are highly soluble in pure water. Most minerals do notnoticeably dissolve in water, even after weeks or months. But in a weak acid, many mineralsdissolve. This happens because the acid breaks the bonds that hold the mineral’s atomstogether within the mineral’s crystal structure. Acid contains hydrogen ions, which are goodat breaking chemical bonds in certain minerals, particularly carbonate minerals. Theseminerals release carbon dioxide gas (CO2) as they dissolve in the acid.In this exercise you will test the solubility of your five minerals in a weak solution ofhydrochloric acid. Although the acid is weak, don’t get it on your hands or clothes. Flushyour eyes with water if you get any acid in them. Record your observations in the tablebelow.Mineral Did gas form? If yes, fast or slow? Fizzing sound? Other observations12345Calcite is c alcium carbonate (CaCO3). All carbonate minerals have relatively weakbonds, so they dissolve in even the weakest acids. This dissolution is commonplace in naturebecause ordinary rainwater generally is slightly acidic. The natural source of the acidity inrainwater is carbon dioxide gas. Carbon dioxide is a natural part of Earth’s atmosphere,and it dissolves into raindrops to form weak carbonic acid. Calcite is the only one of yourfive samples that is a carbonate mineral. Based on the experiment you just did, which oneis it?Fill this information in the table on page 1.Luster4.1 Luster is a description of how light is reflected off a mineral. The two basic categoriesof lus ter are metallic and non-metallic. Within the non-metallic category are several other3Geosc 001 Spring 2006 Lab 2descriptors, such as glassy, earthy (dull), pearly, silky, or resinous. Try to classify each ofyour five samples in terms of these descriptors.Mineral Luster If non-metallic, other description12345The only mineral of your five with a metallic luster is magnetite. Which one is it?Fill this in the table on page 1.Color and StreakUsing the streak plates, scratch each mineral along the plate to determine its streak color,if any.Mineral Mineral color Streak color12345Double RefractionTake each of your transparent mineral samples and put them down on a piece of paper withtext or a line drawn on it. Which one of them splits the image into two images?4Geosc 001 Spring 2006 Lab 2Crystal HabitThe atomic structure (the arrangement of the crystal lattice) of a mineral determines itshabit, the shape into which it grows. Habit is generally a geometric description, such as“cubic”, or “fibrous”, or “prismatic”, etc. Try to describe the habit of each of your samples.Mineral Crystal Habit12345CleavageThe atomic structure (the arrangement of the crystal lattice) of a mineral also determinesits cleavage, the shape into which it breaks. Note that habit and cleavage may be different.Often a mineral will grow in one shape, but it w ill fracture in another shape based on whereits lattice bonds are weak. Crystals often break in a way that produces one or more s moothsides.Refer to the rock and mineral id sheets for examples of different types of cleavages.Some minerals have no preferred shape when they break and these are defined as having nocleavage. Try to desc ribe the cleavage (if present) of each of your mineral samples.Mineral Cleavage12345HardnessRefer to the following two tables for help with this exercise. Use your fingernails and thepenny, steel nail, glass plate, and s treak plate provided to