Gemstones Flashcards
1
Q
Amber
A
Amorphous Isotropic Hardness - 2 1/2 Stability - Poor Toughness - Poor Resinous Lustre Locality - Baltic Sea, Dom Rep and Mexico
2
Q
Beryl - Emerald
A
Hexagonal - Uniaxial Anisotropic Beryllium aluminium silicate Hardness - 7 1/2 Stability - Fair Toughness - Poor Colouring element - Chromium and sometimes vanadum Locality - Columbia, Brazil, India, Pakistan, Siberia, South Africa, Zambia and Zimbabwe CCF - Pink or red
3
Q
Beryl - Aquamarine
A
Hexagonal - Uniaxial Anisotropic Colouring element - Iron Hardness - 7 1/2 Stability - Good Toughness - Good Locality - Brazil, Kenya, Madagascar, Burma, Nigeria, Ural Mountains, Sri Lanka, USA, Zambia, Zimbabwe
4
Q
Beryl - Heliodor
A
Hexagonal - Uniaxial Anisotropic Hardness - 7 1/2 Stability - Good Toughness - Good Colouring element - Iron
5
Q
Other Varieties of Beryl
A
Morganite - Peach/pink Red Beryl - AKA Bixbite, locality USA, colouring element manganese Goshenite - colourless, USA Brown Beryl Pezzottaite - pink/red
6
Q
Beryl - Synthetic
A
FLUX MELT INCLUSIONS Twisted veils - flux droplets in healed fractures platinum inclusions from crucible HYDROTHERMAL INCLUSIONS Spiky nail head cavities capped with crystals zigzag zones heat haze like structure growth marks
7
Q
Chrysoberyl
A
Orthorhombic - Biaxial Beryllium aluminium oxide Colouring element - Iron Hardness - 8 1/2 Stability - Very Good Toughness - Excellent to Good Three way triling gives psuedohexagonal habit Localities - Brazil, Sri Lanka, Madagascar, Burma, Zimbabwe
8
Q
Chrysoberyl - Cats Eye
A
Caused by fine parallel needles or hollow tubes
9
Q
Chrysoberyl - Alexandrite
A
Colouring Element - Chromium Red in Tungsten and candlelight Green in Daylight Locality - Brazil Dichroscope - traffic light - Red, orange, green
10
Q
Corundum - Ruby
A
Trigonal - Uniaxial Aluminium Oxide Birthstone - July Colouring element - Chromium Hardness 9 Stability - Very Good Toughness - Excellent Localities - Burma, Pakistan, Afghanistan, Thailand, Sri Lanka, Tanzania, Vietnam CCF - Red
11
Q
Corundum - Sapphire
A
Trigonal - Uniaxial Aluminium Oxide Birthstone - September Colouring element - Titanium and Iron Hardness 9 Stability - Very Good Toughness - Excellent Localities - India, Burma, Thailand, Sri Lanka, Cambodia, USA, Australia
12
Q
Corundum - Synthetic
A
VERNEUIL FLAME FUSION INCLUSIONS
Curved growth lines
gas bubbles
FLUX MELT INCLUSIONS
flux filled cavities and healed fractures
platinum platelets
flux particles arranged in steamer or comet like patterns
13
Q
Feldspar - Moonstone
A
Monoclinic - Biaxial Potassium aluminium silicate Birthstone - June Hardness - 6 Stability - Good Toughness - Poor Localities - Sri Lanka, India, Burma
14
Q
Feldspar - Labradorite
A
Triclinic - Biaxial Calcium, sodium aluminium silicate aka Spectrolite Hardness - 6 Stability - Good Toughness - Poor Localities - Australia, Canada, Finland
15
Q
Feldspar - Sunstone
A
Triclinic - Biaxial
Spangles effect caused by platy inclusions
hematite plates
16
Q
Feldspar - other
A
AMAZONITE - microcline, colarado
OREGON SUNSTONE - pale yellow/pink, Oregon
ORTHOCLASE - colourless to yellow, Madagascar
