5.48ct Chrome Tourmaline rough, side view
5.48ct Chrome Tourmaline rough, side view
5.48ct Chrome Tourmaline rough, pavilion view
5.48ct Chrome Tourmaline rough, side view
5.48ct Chrome Tourmaline rough, side view

5.48CT Chrome Tourmaline Faceting Rough | Uncut Gemstone

$328.80

Vivid green 5.48CT Chrome Tourmaline Rough from Tanzania. Eye clean clarity, 12.82×11.11×5.08mm. Blocky shape is ideal for high yield round or oval cuts.

1 in stock

SKU: i96BPzR1T6U Categories: ,

Technical Specifications & Gemological Properties

Specifications for 5.48CT Chrome Tourmaline Faceting Rough
Carat Weight 5.48CT
Dimensions 12.82 × 11.11 × 5.08mm
Origin Tanzania
Treatment None known
Color Vivid Green
Clarity Grade Eye Clean
Gem family Tourmaline
Variety Chrome Tourmaline
Refractive Index 1.62–1.64 †
Hardness (Mohs) 7–7.5 †
Optic Character Doubly refractive, uniaxial (−), birefringence 0.018–0.020 †
Pleochroism Moderate to strong (dichroic) †
Specific Gravity 3.02–3.26 †

† Typical reference value for tourmaline; individual stones vary.

How to orient and cut this rough — Lapidary Guide

Description

Eye clean clarity means the cutter can focus on the 5.48CT Chrome Tourmaline Rough without avoiding visible inclusions. This vivid green facet rough comes from Tanzania. The color often appears darker when you look down the C-axis. The 12.82×11.11×5.08mm blocky shape allows for a high yield. This rough is suitable for emerald or oval shapes.

5.48CT Chrome Tourmaline Rough Specifications

  • Lapidary notes: Blocky shape for high yield; Clean rough; Open C-axis

Cutting Notes

The C-axis is open in this stone. You can place the table across the C-axis to keep the green color light. You can place the table parallel to the C-axis for a darker tone. The blocky dimensions support a wide variety of shapes with minimal waste. The rough is clean, so you can plan the facet arrangement based on the blocky shape.

Chrome Tourmaline is brittle and sensitive to heat. You must keep the stone cool during the grinding process. Avoid heavy pressure on the lap to prevent fractures. The material has a critical angle of about 38 degrees. You must cut pavilion angles above this limit to prevent light leakage and windowing. Birefringence is high, so you may see doubled facet edges.

Cutter’s tip: Use the open C-axis to calibrate the final color saturation before you preform the crown.

Every stone is filmed on video before it is listed, so what you see is the stone you get. For background on Chrome Tourmaline, see the GIA Tourmaline guide. Browse more Chrome Tourmaline faceting rough from Jackson’s Gems.

Related Guides

New to cutting Tourmaline? See the Lapidary Guide.

Questions About This Chrome Tourmaline Rough

How does the C-axis affect the color of Chrome Tourmaline?

The stone is strongly pleochroic. The color usually looks darker when viewed down the C-axis and lighter when viewed across it.

What is the critical angle for this material?

The critical angle is about 38 degrees. Pavilion angles near or below this value cause light to leak out of the stone.

Why must I keep the stone cool during grinding?

Chrome Tourmaline is heat sensitive. Excessive heat during faceting can damage the stone or affect its properties.

What is the Mohs hardness of Chrome Tourmaline?

It has a Mohs hardness of 7 to 7.5. This makes it durable for jewelry but still requires care during polishing.

Does Chrome Tourmaline show doubling of facet edges?

Yes, because the birefringence is between 0.018 and 0.020. This is high enough that you can see doubled edges through the gem.

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