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A Treatise for Gemcutters - Gem Glossary (A)

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[!] A series of aged manuscripts packed within leather-backed tomes would begin to circulate, originating from Southern Arcas. Bereft of silvering or golden trims, the following title was embossed on the cover; elegant print would follow after. Although unsigned, denizens of the Under-Realm, Aegrothond, and Fenn might discern the manuscript’s writer more precisely. Overall, it appears as though this document is a fraction of a larger encyclopedia.

 

II. Gemstone Glossary

 

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Chapter Introduction

 

Following interview with the client and the commission being defined, it is wise for any silversmith or gemcutter to assess his stock of gems. No stone is alike, and keen eyes are suitable for the selection in order to proceed forward. The following is a selection of observed gems produced through natural causes1. Tables of definitions lay before this, for ease of reading.

 

Definitions

Cabochon – A polished gem lacking facets.

Clarity - A gem’s presence (or lacking) of inclusions. Higher clarity equates to fewer inclusions observable by the natural eye (and magnification)

Cut – Describes the placement, presence and number of facets of a gem.

Facet – A flat surface of a multiple-sided gem, produced by cutting.

Group – A category of gems determined by the mineral composition.

Hardness – Describes a gem’s surface resistance to abrasion. Positive correlation with strength.

Inclusions – A material trapped within the gem, acquired by natural formation. Inverse correlation to clarity.

Luster – Describes the surface of the gem and its reflection of light. (See Lustre Terminology)

Shape – The face-up outline of a gemstone.

Toughness – A gem’s resistance to cracks, chips and breakage.

Variety – A type of gem within a group.

 

Lustre Terminology

Adamantine – Highly refractive, translucent, and transparent.

Metallic – Quality of polished metal, flat surfaces are reflective.

Pearlescent – Possessing a thin layer of transparency, reflective like its namesake.

Silky – Parallel, often uniform fibers.

Greasy – Smooth, akin to oil, due to various inclusions.

Resin – Transparent, bearing the appearance of resins such as amber.

Vitreous – Similar to glass.

Waxed – Soft, smooth appearance.

Dull – Coarse, very little reflection of light.

 

Gemstones

Precious Gems2

Diamond

The strongest of natural gemstones, known for its superior qualities. Often valued in weight.

Clarity medium or poor due to mining; high clarity is in high demand and value.

Colors – white (common), yellow, brown, green, pink, blue, black, red purple

Cuts – proportions often altered to maximize color and reflection of light; often associated with the ‘brilliant cut’

Hardness – May scratch Corondum

Lustre – Adamantine

Toughness – High; fatally, contains directions of cleavage within (difficult to break, but possible)

 

Emerald

Prominently known for its range of green color, from hues of blue to yellow. Prone to inclusions.

Group – Beryl

Clarity low, featuring many inclusions; high clarity common in larger gems.

Colors – green, depends on locale

Cuts – corners often removed to prevent later breakage, creating the ‘emerald cut’; straight cuts are common and usual.

Hardness – may scratch glass

Lustre – Vitreous

Toughness – poor

 

Ruby

Valued for its natural red color and fine lustre.

Group – Corondum

Clarity low; inclusions valued for star-patterning, susceptible to heat for treatment

Colors – red, rarely pink hues

Cuts – a fine cut on a gem with few inclusions bears a fine lustre; round shapes are more rare than oval; square/emerald cuts often yield larger gems

Hardness – may scratch topaz

Lustre – Bright Vitreous

Toughness – good, if lacking inclusions

 

Sapphire

Category of Corondum including all other colors, typically blue.  A welcome gemstone choice – customers frequently associate this gem with blue (beware).

Group – Corundum

Clarity low; inclusions valued for star-patterning, susceptible to heat for treatment; high clarity is extremely rare.

Colors – blue (common), pink, yellow, green, purple, black

Cuts – similarly to rubies, preferring oval over round shapes; 

Hardness – may scratch topaz

Lustre – Vitreous

Toughness – good, if lacking inclusions

 

False Ruby/ Sapphire

A peculiar variety of gem I mistook for a ruby or sapphire. Although similar in composition to these gems, it possesses a lower hardness, and is just as lustrous.

Clarity low, fewer inclusions than a ruby.

Colors – soft red (common), deep blue, pink

Cuts – suitable for pillow shapes, often in small forms

Hardness – may scratch topaz

Lustre – Bright Vitreous

Toughness – good, if lacking inclusions

 

[!] Rather abruptly, it seems the chapter has been cut off before the Chapter’s Appendix. Context of the latter notes suggest the section on ‘Semi-Precious’ Gems to be missing. Penned at the bottom of a page’s corner was the name Fi’Annyerir.

 


Appendix

1. Although there exist gemstones which attain lustre through unconventional means, these gems are valued for inherent functional properties as opposed to natural beauty. Such gems are typically acquired and refined for the sake of wards, socketed into weapons, etc. A gemcutter is likely able to refine such gems through mundane means. However, the Arcane is volatile – sudden ruptures are likely to shatter a gem from within.

2. Refrain from using ‘precious’ versus ‘semi-precious’ among certain circles of gemcutters. These terms are perceived as arbitrary for the sake of their work. These terms are devised for the sake of patrons. Categorization of gems eases the simple man’s eyes.

 

 

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