How TGB works

We identify the stone using established gemmological and trade-recognized terminology.

By Species, followed by the Variety.

We assess the stone using structured criteria.

Color

• Tone (1–10)
  
• Saturation (1–10)
  
• Consistency
  

Clarity

• Visibility and impact of inclusions
  
• Assessed relative to the material
  

Cut

• Windowing
  
• Extinction
  
• Symmetry
  
• Polish
  
• Spread
  

Treatment

• Disclosed based on evidence
  
• No assumptions beyond verification

We translate observations into a consistent internal framework.

• No subjective language
  
• No exaggerated descriptors
  
• No shifting standards between stones
  

Pricing is determined from the same structured evaluation applied to every stone.

Color, clarity - relative to species, cut, treatment, size and rarity are considered together, not selectively.

Pricing is not adjusted through language or presentation.

We use only recognized gemmological and trade terminology.

No invented or marketing-driven language.

We state what is known and what can be verified.

We do not infer beyond available evidence.

The same framework is applied across all stones, regardless of value or rarity.

We do not make claims that cannot be supported.

This includes:

• Speculative origin
  
• Overstated color descriptions
  
• Assumed treatments
  
• Investment positioning

Images are captured under controlled conditions:

• Neutral backgrounds
  
• Consistent lighting
  
• No artificial color enhancement
  
• Minimal post-processing
  

Images are intended to represent, not persuade.

To know more about our photography standards click here.

Each stone follows a fixed structure

Format does not change based on value or rarity.

Each stone is accompanied by a TGB certificate reflecting the same structured framework used across all listings.

This includes:

• Classification
  
• Color (tone & saturation)
  
• Clarity
  
• Treatment disclosure
  
• Key identifying details
  

Independent laboratory reports are available on request.

Where applicable, certification can be arranged prior to purchase.

Certification is used to support clarity, not to define it.