Natural Black Tourmaline Stone — 4.78 Carat (5.25 Ratti)
Photos: Use the main, back, in-hand, and side photos on this page to judge colour, polish, and size.
What you are buying: This is a natural dark tourmaline sold in the trade as black tourmaline (typically schorl). It weighs 4.78 carat (about 5.25 ratti) in an Oval Mixed Cut — a classic oval style for rings and pendants. Ratna Gems lists this item as natural tourmaline. If testing or identification paperwork is included with your shipment, read it for that provider’s conclusions and measurements.
Documentation: If a gem testing report is included with your order, it is the official source from that laboratory only for whatever that document states. Report layout and field labels vary; we do not reproduce your specific document here.
Colour: Ratna Gems specification: greenish black — reads as black face-up, with a possible soft green hint under some lighting. That is common for black tourmaline. Photos show this actual stone. The title uses “black tourmaline” for search. Compare any colour fields on paperwork you receive, if provided.
Gem facts: Black gem tourmaline is usually the iron-rich type gemologists call schorl. The Gemological Institute of America (GIA) states that tourmaline has Mohs hardness about 7 to 7.5 — durable for jewelry if you avoid hard knocks. GIA also notes tourmaline can show electrical effects when heated or pressed (pyroelectric / piezoelectric) — a science fact, not something you feel in normal wear.
Size: About 12.5 mm × 9.5 mm × 5.5 mm. Share these numbers with your jeweler for mounting.
| Detail | Value |
|---|---|
| Weight | 4.78 Carat (5.25 Ratti) |
| Size (L × W × H) | 12.5 × 9.5 × 5.5 mm |
| Colour (Ratna Gems specification) | Greenish Black |
| Shape / cut | Oval Mixed Cut |
| Transparency | Opaque (light does not pass through this stone) |
| Luster | Vitreous (glass-like shine, typical for natural tourmaline) |
| Chemical composition | Iron-rich tourmaline (schorl type) — complex boron aluminium silicate. Reference formula: NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄ |
| Stone type / variety | Natural Tourmaline — black tourmaline (schorl) |
| Hardness | 7.0 to 7.5 on Mohs scale (see GIA tourmaline overview) |
| Specific gravity (typical range, schorl) | About 3.06 to 3.25 |
| R.I. (reference range) | 1.61 to 1.65 — typical range for this material; confirm against any documentation supplied with your order. |
| Treatment | Un-Heated & Un-Treated |
| Indian / trade name | Vikrant Mani |
| Material (Ratna Gems listing) | Natural tourmaline (black tourmaline / schorl) — how we describe and sell this stone. Verify wording on any authentication paperwork included with your purchase. |
Why people buy black tourmaline
Many buyers want a natural, dark, affordable gemstone that looks bold in gold or silver. It works for both dress and daily wear if the setting protects the stone.
Astrology and belief (read this)
Black tourmaline is not one of the classical Navratna (nine gems) in old Jyotish texts. It is not a substitute for blue sapphire (Neelam) in classical lists. In today’s market it is often sold for jewelry or personal / Vastu-style belief. Some people treat it as easy to wear for general use, but that is belief, not a rule. We do not promise health, luck, or astrological results. For chart-based advice, talk to an astrologer you trust.
Is this stone right for you?
Choose this if you want a natural black tourmaline of about 4.78 carat in an oval cut. For heavy hand use, ask your jeweler for a bezel or strong prong setting.
Simple care
- Clean with warm water, mild soap, and a soft brush.
- Avoid sudden heat–cold shock and harsh chemicals.
- Store apart from softer gems so it does not scratch them.
Browse our Tourmaline Stone range. For a full buyer’s article, see the Black Tourmaline complete guide.
