Twinned Crystals                            
Cochise College                                                                                        
Geology Home Page 
MINERALS and CRYSTALS

Crystals and Crystal Models    

Roger Weller, geology instructor ( wellerr@cochise.edu )
last edited:  3/22/18    number of photos:  42 
 

also visit:
Textbook of Systematic Mineralogy
by Hilary Bauerman, 1881, 362 pages
    Twinned Crystals- page 166

wooden crystal models
   model 50-octahedron twin:  1  2  3  4
   model 52-interpenetration twin of cubes:  1  2
   model 82:  1  2  3  4
   model 196-gypsum-swallowtail twin:  1  2  3
   model 197:  1  2  3  4  5

                                                                                   

mineral examples of twinned crystals    
   
aragonite:  1  2
    calcite:  1  2  3
    cerussite:  1  2
    feldspar-orthoclase:  1  2  3  4
    feldspar-polysynthetic twinning:  1  2  3
    gypsum:  1  2
    quartz:  1  2
    sphalerite:  1  2  3
    staurolite:  1  2  3

click here:  link to line drawings of twinned crystals
371 twinned crystal forms

Photos are copyright free for non-commercial educational uses. 
Just credit photos to R.Weller/Cochise College.                                                     
Copyright 2018 R.Weller