Stone 03 · Gemstone guide
Blue Sapphire
Neelam
Blue sapphire is blue corundum, coloured principally by trace-element interactions involving iron and titanium. It combines high hardness with a wide range of tones and colour distribution.
Gemological register
- Mineral
- Corundum
- Composition
- Aluminium oxide
- Crystal system
- Trigonal
- Mohs hardness
- 9
- Refractive index
- About 1.762 to 1.770
- Specific gravity
- About 4.00
Colour
Colour is a range, not a shorthand.
Hue may move from violetish blue to greenish blue, with tone ranging from light to very dark. Colour zoning is common, so orientation and cut strongly affect the visible result.
Clarity and character
Read inclusions in context.
Crystal inclusions, needles, healed fractures and growth zoning can occur. Clarity is considered with colour and durability, not used as a single measure of quality.
Treatment disclosure
Ask what changed and how it was detected.
Heating is common and may alter colour or clarity. Lattice diffusion, fracture filling and other processes must be distinguished from heat-only material and clearly disclosed.
Setting practice
The mount answers the material.
Corundum tolerates many setting styles, but inclusions and facet junctions still guide pressure. The mount should protect the girdle while allowing inspection and routine cleaning.
Care
Care follows the individual record.
Use lukewarm water, mild soap and a soft brush for routine care when the disclosure permits it. Filled stones need special caution, and all settings should be checked after impact.
Sourcing questions
Questions worth carrying to the desk.
- 01What treatment conclusion accompanies the stone?
- 02Is a stated geographic origin supported by a laboratory opinion?
- 03How does colour zoning appear in ordinary light?
- 04Are there inclusions that affect the proposed setting?
Kundali note
Blue sapphire is traditionally associated with Shani in Jyotish. IshaRa discusses it only within a considered personal consultation, without predicting or guaranteeing an effect.
Traditional association and gemological assessment remain distinct parts of a conversation. No material is presented as an outcome guarantee.
Read the consultation process →Individual assessment
Ask about a stone, setting or record.
Bring the object, report language or sourcing question you want to study. The next step is a direct conversation.
Begin a conversation