Assignment 9 - Finding and Identifying Clarity Characteristics Flashcards
Internal or external feature of a gemstone that helps determine its quality and establish its identity
Clarity characteristic
What makes clarity characteristics important?
Clarity characteristics determine a stone’s clarity grate, help set its value, and help identify it.
What part of the examination most influences a clarity grade?
Your first impression of a diamond’s face-up appearance should strongly influence its clarity grade.
Clarity characteristic totally enclosed in a polished gemstone or extending into it from the surface
Inclusion
Clarity characteristic that’s confined to the surface of a polished gemstone
Blemish
A position that orients a gemstone’s crown facets and table toward the viewer
face-up
Lighting a diamond from the side against a black, non-reflective background.
Darkfield illumination
Lighting a diamond from below to create a bright background
Brightfield illumination
What tools are used for clarity grading?
Loupe or Microscope
The distance that’s clear and sharp above and below a point you focus on with a magnifier
Depth of field
What are the 4 most common internal inclusions?
- Crystal (Xtl)
- Needle (Ndl)
- Pinpoint (Pp)
- Cloud (Cld)
What are the 9 most common surface reaching inclusions?
- Feather (Ftr)
- Etch Channel (EC)
- Bearded Girdle (BG)
- Bruise (br)
- Knot (K)
- Patch of Color (Patch)
- Chip (Ch)
- Cavity (Cav)
- Indented Natural (IN)
What are some rare clarity characteristics?
Inclusions that look like animals etc.
What are the 3 most common blemishes caused by wear?
- Nick (Nck)
- Abrasion (Abr)
- Scratch (Scr)
What are the 8 most common blemishes from cutting?
- Extra Facet (EF)
- Polish Mark
- Lizard Skin (LS)
- Polish Lines (PL)
- Burn (Brn)
- Dop Burn (Dop)
- Rough girdle (RG)
- Pit (Pit)
What are the 2 most common blemishes resulting from crystal structure?
- Natural (N)
- Surface Graining (SG)
What are the two most common inclusions cause by laser treatment?
- Laser Drill-hole (LDH)
- Internal Laser Drilling (ILD)
A trade term for any break in a diamond
Feather
A flash of changing color seen in a fracture-filled diamond when you look parallel to the filled inclusion and rock the diamond back and forth under magnification.
Flash effect
Treatment that involves injecting a molten glass substance into a diamond’s surface-reaching feathers or laser-drill-holes
Fracture filling
What does chromatic aberration cause?
A rainbow effect around the viewing field
What does spherical aberration cause?
Straight lines appear to bend around the edges of the viewing field.
What type of loupe has been corrected for color distortion and linear distortion?
Triplet loupe.
What is the abbreviation for an inclusion that is a result of crystal distortion during growth?
Twinning Wisps (TW)
