$280Sale Price|20% Off
1.70 Carat Natural Loose Rubellite Tourmaline Cushion Shape Gemstone
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 1.70 Carat Dimension: 7.3 x 7.1 x 4.1 Mm Colour: Pink Certificate: On Customer Demand Shape: Cushion Tourmaline is a captivating gemstone kno...
Rubelite, Tourmaline
$320Sale Price|20% Off
3.20 Carat Rubellite Tourmaline Cushion Gemstone from Afghanistan
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 3.20 Carat Dimension: 10.2 x 9.5 x 5.2 Mm Colour: Maroon Treatment: Non Certificate: On Customer Demand Shape: Cushion Tourmaline is a capti...
Tourmaline, Rubelite
25.35 Carats Paraiba Tourmaline mix Cut stone For Fine Jewelry Natural Gemstone
Located in Jaipur, RJ
25.35 Carats Paraiba Tourmaline mix Cut stone For Fine Jewelry Natural Gemstone Gemstone - paraiba tourmaline Weight - 25.35 Carats Shape - Mix cut Size - 4.5x5-9x7 MM Pieces - 22
Rubelite, Tourmaline, Paraiba
$640Sale Price|20% Off
2.15 Carat Stunning Faceted Rubellite Tourmaline Cushion Shape Gemstone
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 2.15 Carat Dimension: 8.7 x 7 x 5.1 Mm Colour: Pink Treatment: Non Certificate: On Customer Demand Shape: Cushion Tourmaline is a captivatin...
Rubelite, Tourmaline
$640Sale Price|20% Off
13.30 Carat Excellent Loose Rubellite Tourmaline Oval Shape Gem For Pendant
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 13.30 Carats Dimension: 19.1 x 14.3 x 8 Mm Origin: Afghanistan Shape: Oval Color: Pink Certificate: On Demand Rubellite tourmaline, often regard...
Rubelite, Tourmaline
$640Sale Price|20% Off
2.15 Carat Excellent Faceted Rubellite Tourmaline Cushion Shape Gemstone
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 2.15 Carats Dimension: 8.7 x 7 x 5.1 Mm Origin: Afghanistan Shape: Cushion Certificate: On Demand Rubellite tourmaline, often regarded as the "l...
Rubelite, Tourmaline
1.8 cts Pear Shape Rubellite Tourmaline Gemstone for Jewelry 9 mm
Located in Peshawar, PK
Gemstone Details: Faceted Rubellite Tourmaline Weight 1.85 carats Dimension 9.3 x 7.8 x 4.8 mm Origin Afghanistan Treatment Standard Heated accepted in trade Shape and Cut Pear ...
Rubelite
21.50 Carats Rubellite Tourmaline Oval Cut stone For Jewelry Natural gemstone
Located in Jaipur, RJ
21.50 Carats Rubellite Tourmaline Oval Cut stone For Jewelry Natural gemstone Gemstone - Rubellite Tourmaline Weight - 21.50 Carats Shape - Oval cut Size - 21x17.5x9 MM Pieces - 1
Rubelite, Tourmaline
$4,760Sale Price|20% Off
Reddish Pink Natural Rubellite Tourmaline Ring Loose Gemstone 9.40Ct Cushion Cut
Located in Peshawar, PK
Reddish Pink Natural Rubellite Tourmaline Loose Gemstone for Ring, Necklace Pendant or any other Jewelry Setting-Cushion Cut 💎 GEMSTONE TYPE: Rubellite Tourmaline ⚖️ WEIGHT: 9.40 ...
Rubelite, Tourmaline
$538Sale Price / set|30% Off
Hot Pink Natural Rubellite Tourmaline 3.14 Carat Emerald Cut Loose Gemstone Pair
Located in Peshawar, PK
Vivid Hot Pink Natural Rubellite Tourmaline Loose Gemstone Pair for Earrings, Bracelet, Pendant or any other Jewelry Setting!! 💎 GEMSTONE TYPE: Tourmaline ⚖️ WEIGHT: 3.14 Carat 🪚 ...
Rubelite, Tourmaline, Emerald
$1,945Sale Price|35% Off
Reddish Pink Natural Rubellite Tourmaline Ring Loose Gemstone 6.65Ct Cushion Cut
Located in Peshawar, PK
Reddish Pink Natural Rubellite Tourmaline Loose Gemstone for Ring, Pendant or any other Jewelry Setting Cushion Cut from Kunar, Afghanistan!! 💎 GEMSTONE TYPE: Rubellite Tourmaline ...
Rubelite, Tourmaline
25.21 Carats Top Quality Rubellite Tourmaline Cabochon 3 Pieces Natural Gemstone
Located in Jaipur, RJ
Gemstone - Rubellite Tourmaline Weight - 25.21 Ct Size - 9.5 To 16x11 MM Piece - 3 Shape - Cabochon & Round
Rubelite, Tourmaline
17.88 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone
Located in Jaipur, RJ
17.88 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone Gemstone - Rubellite Tourmaline Weight - 17.88 Carats Shape - Cushion Size - 13x12x8-12x12.5x8 MM Pi...
Rubelite, Tourmaline
$360Sale Price|20% Off
3.15 Carat Natural Loose Rubellite Tourmaline Square Shape Gemstone
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 3.15 Carat Dimension : 8.4 x 8.3 x 6.5 Mm Origin: Afghanistan Colour: Pink Treatment: Non Certificate: On Customer Demand Tourmaline is a ca...
Rubelite, Tourmaline, Other
Certified Pinkish Red Natural Rubellite Tourmaline 12.21 Ct Cushion Cut Gemstone
Located in Peshawar, PK
Natural Rubellite Tourmaline Pinkish Red Cushion Cut Loose Gemstone, ICA Certified Earth-Mined Genuine Pink Red Tourmaline Jewelry Stone, Fine Gemstone for Ring, Earrings, Pendant, C...
Tourmaline, Rubelite
$26,080Sale Price|20% Off
81.50 Carats Rubellite Layout Oval Top Quality For Fine Jewelry Natural Gem
Located in Jaipur, RJ
81.50 Carats Rubellite Layout Oval Top Quality For Fine Jewelry Natural Gem Gemstone - Rubellite Tourmaline Weight - 81.50 Ct Size - 6.5x8 To 8x10 MM Pieces - 34 Shape - Oval
Rubelite, Tourmaline
7.18 Carat Natural Rubellite Tourmaline, Oval Cut Loose Gemstone
Located in Khet Bang Rak, 10
About Rubellite Rubellite is a prized variety of tourmaline, known for its vibrant pink to red tones and its ability to retain colour beautifully under different lighting conditions....
Rubelite, Tourmaline
$480Sale Price|20% Off
1.50 Carat Splendid Loose Rubellite Tourmaline Shield Cut Gem For Necklace
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 1.50 Carats Dimension: 9.2 x 7 x 4.3 Mm Origin: Afghanistan Shape: Shield Color: Pink Certificate: On Demand Rubellite tourmaline, often regarde...
Rubelite, Tourmaline
$520Sale Price|20% Off
2.35 Carat Pretty Loose Rubellite Tourmaline Pear Shape Gemstone
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 2.35 Carat Dimension: 11.9 x 6.6 x 4.9 Mm Colour: Pink Certificate: On Customer Demand Shape: Pear Tourmaline is a captivating gemstone known...
Rubelite, Tourmaline
22.47 Carats Paraiba Tourmaline Oval Cut stone For Fine Jewelry Natural Gemstone
Located in Jaipur, RJ
22.47 Carats Paraiba Tourmaline Oval Cut stone For Fine Jewelry Natural Gemstone Gemstone - paraiba tourmaline Weight - 22.47 Carats Shape - Oval cut Size - 8x10-9x12 MM Pieces - 6
Rubelite, Tourmaline, Paraiba
$9,789Sale Price|30% Off
Reddish Pink Natural Rubellite Tourmaline Ring Loose Gemstone 13.2Ct Cushion Cut
Located in Peshawar, PK
Reddish Pink Natural Rubellite Tourmaline Loose Gemstone for Ring, Necklace Pendant or any other Jewelry Setting-Cushion Cut 💎 GEMSTONE TYPE: Rubellite Tourmaline ⚖️ WEIGHT: 13.20...
Rubelite, Tourmaline
$640Sale Price|20% Off
By Gilt Gems 2.40ct Square Cut Rubellite Tourmaline, Afghanistan
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 2.40 Carat Dimension: 7.4 x 7.4 x 6.4 Mm Colour: Pink Treatment: Non Certificate: On Customer Demand Shape: Square Tourmaline is a captivati...
Tourmaline, Rubelite
23.97 Carats Top Quality Rubellite Tourmaline Cabochon Sugarloaf Natural Gem
Located in Jaipur, RJ
This is a one of a kind of rubellite tourmaline. Gemstone - Rubellite Tourmaline Weight - 23.97 Ct Size - 15.4x13.14 MM Piece - 1
Rubelite, Tourmaline
$320Sale Price|20% Off
0.90 Carat Adorable Loose Rubellite Tourmaline Pear Shape Gemstone
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 0.90 Carats Dimension: 8.3 x 4.7 x 3.6 Mm Origin: Afghanistan Shape: Pear Color: Pink Certificate: On Demand Rubellite tourmaline, often regarde...
Rubelite, Tourmaline
$640Sale Price|20% Off
5.75 Carat Stunning Faceted Rubellite Tourmaline Oval Shape Gemstone
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 5.75 Carats Dimension: 13.7 x 11.5 x 5.8 Mm Origin: Afghanistan Shape: Oval Certificate: On Demand Rubellite tourmaline, often regarded as the ...
Rubelite, Tourmaline
6.28 Carats Rubellite Tourmaline Pear Cut stone For Jewelry Natural Gemstone
Located in Jaipur, RJ
6.28 Carats Rubellite Tourmaline Pear Cut stone For Jewelry Natural Gemstone Gemstone - Rubellite Tourmaline Weight - 6.28 Carats Shape - Pear cut Size - 16x10x6.5 MM Pieces -
Rubelite, Tourmaline
10.69 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone
Located in Jaipur, RJ
10.69 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone Gemstone - Rubellite Tourmaline Weight - 10.69 Carats Shape - Cushion cut Size - 13.5x13.5x8.15 MM ...
Rubelite, Tourmaline
$880Sale Price|20% Off
5.50 Carat Natural Loose Rubellite Tourmaline Stone Cushion Cut Afghan Gemstone
Located in Bangkok, TH
Weight 5.50 carat Dimensions 11.0x10.3x6.6mm Treatment None Origin Afghan Clarity SI Shape Cut Cushion This exquisite 5.50 carat Rubellite Tourmaline showcases a rich, vivid ...
Rubelite, Tourmaline
11.61 Carats Rubellite Cushion Cut Top Quality For Fine Jewelry Natural Gemstone
Located in Jaipur, RJ
11.61 Carats Rubellite Cushion Cut Top Quality For Fine Jewelry Natural Gemstone Gemstone - Rubellite Weight - 11.61 Carats Shape - Cushion cut Size - 15x12.5x8.3 MM Pieces - 1
Rubelite, Tourmaline
$640Sale Price|20% Off
4.70 Carat Glamorous Loose Rubellite Tourmaline Oval Shape Gem For Jewellery
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 4.70 Carats Dimension: 11.8 x 10 x 5.9 Mm Origin: Afghanistan Shape: Oval Color: Pink Certificate: On Demand Rubellite tourmaline, often regarde...
Rubelite
$640Sale Price|20% Off
2.30 Carat Good Looking Faceted Rubellite Tourmaline Cushion Shape Gemstone
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 2.30 Carats Dimension: 8.3 x 7.5 x 4.8 Mm Origin: Afghanistan Shape: Cushion Color: Pink Certificate: On Demand Rubellite tourmaline, often rega...
Rubelite, Tourmaline
$1,467Sale Price|30% Off
7.20 Carat Hot Pink Natural Rubellite Tourmaline, Cushion-Cut Loose Gemstone
Located in Peshawar, PK
Rare Hot Pink Natural Rubellite Tourmaline Loose Gemstone, Cushion-Cut, High-Quality Rare Color Gem for Custom Fine Cocktail Ring, Designer Jewelry, Pendant, Statement Ring, Fine Han...
Tourmaline, Rubelite
$1,866Sale Price / set|30% Off
9.16 Carats Hot Pink Natural Rubellite Tourmaline, Cushion-Cut Loose Gemstones
Located in Peshawar, PK
Rare Hot Pink Natural Rubellite Tourmaline Loose Gemstones, Cushion-Cut, High-Quality Rare Color Gems for Custom Fine Cocktail Ring, Designer Jewelry, Pendant, Statement Ring, Fine H...
Rubelite, Tourmaline
$520Sale Price|20% Off
Gorgeous Rich Color Loose Included Rubellite Tourmaline 5.50 Carat Cushion Shape
Located in Peshawar, PK
Gemstone Type : Rubellite Tourmaline Weight : 5.50 Carats Dimensions : 12.3x8.9x6.6 Mm Origin : Africa Clarity : Inclusion/ Included Shape: Cushion Color: Pink Red Certificate: O...
Rubelite, Tourmaline
$360Sale Price|20% Off
2.50 Carat Incredible Loose Rubellite Tourmaline Oval Shape Gem For Jewellery
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 2.50 Carats Dimension: 8.2 x 7.1 x 5.8 Mm Origin: Afghanistan Shape: Oval Color: Pink Certificate: On Demand Rubellite tourmaline, often regard...
Rubelite
$600Sale Price|25% Off
3.65 Carat Natural Loose Rubellite Tourmaline Cushion Shape Gemstone
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 3.65 Carat Dimension: 10.1 x 8.5 x 5.8 Mm Colour: Pink Treatment: Non Certificate: On Customer Demand Shape: Cushion Tourmaline is a captivat...
Rubelite, Tourmaline
78.00 Carats Rubellite Tourmaline 14 Piece Layout Drops Top Quality Natural Gem
Located in Jaipur, RJ
78.00 Carats Rubellite Tourmaline 14 Piece Layout Drops Top Quality Natural Gem Gemstone - Rubellite Tourmaline Weight - 78.00 Ct Size - 7x10 To 16x12 MM Pieces - 14
Rubelite, Tourmaline
$600Sale Price|20% Off
2.25 Carat Excellent Faceted Rubellite Tourmaline Cushion Shape Gemstone
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 2.25 Carats Dimension: 7.4 x 7.3 x 6.1 Mm Origin: Afghanistan Shape: Square Certificate: On Demand Rubellite tourmaline, often regarded as the "...
Rubelite, Tourmaline
Natural Pink Rubellite Gemstone 9.70 carats / JupiterGem
Located in Los Angeles, CA
Identification: Natural Rubellite 9.70 carats Carat: 9.70 carats Shape: Oval Measurements: 16.19 x 12.01 x 7.45 mm Cut: Brilliant/Step Color: Red Clarity: very eye clean Discover ...
Rubelite
$280Sale Price|20% Off
2.70 Carat Stunning Faceted Rubellite Tourmaline Oval Shape Gemstone
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 2.70 Carats Dimension: 10.9 x 7.3 x 4.8 Mm Origin: Afghanistan Shape: Oval Certificate: On Demand Rubellite tourmaline, often regarded as the "l...
Rubelite, Tourmaline
$320Sale Price|20% Off
3.15 Carat Glamorous Loose Rubellite Tourmaline Emerald Shape Gem For Ring
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 3.15 Carats Dimension: 10.2 x 6.8 x 5.6 Mm Origin: Afghanistan Shape: Emerald Color: Pink Certificate: On Demand Rubellite tourmaline, often reg...
Rubelite
$280Sale Price|20% Off
Faceted 2.10ct Pink Rubellite Tourmaline Cushion Gemstone, Afghanistan
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 2.10 Carat Dimension: 9 x 6.9 x 4.8 Mm Colour: Pink Treatment: Non Certificate: On Customer Demand Shape: Cushion Tourmaline is a captivatin...
Tourmaline, Rubelite
$600Sale Price|20% Off
1.45 Carat Natural Loose Quality Rubelite Tourmaline Marquise Cut Afghan Gem
Located in Bangkok, TH
Weight 1.45 carat Dimensions 13.8x4.8x3.8mm Treatment None Origin Afghan Clarity Loup Clean Shape Cut Marquise This 1.45 Carat Natural Loose Rubelite Tourmaline showcases a v...
Rubelite, Tourmaline
$600Sale Price|20% Off
Old Mine 6.90 Carats Natural Loose Rubellite Tourmaline Africa Mine
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 6.90 Carats Dimension: 14.7x9.4x6 Mm Origin: Africa Shape: Can Baguette Treatment: Non Color: Red Certificate: On ...
Rubelite, Tourmaline
$336Sale Price|20% Off
1.90 Carat Adorable Loose Rubellite Tourmaline Emerald Shape Gem For Jewellery
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 1.90 Carats Dimension: 9.8 x 5.8 x 3.8 Mm Origin: Afghanistan Shape: Emerald Color: Pink Certificate: On Demand Rubellite tourmaline, often rega...
Rubelite, Tourmaline
$240Sale Price|20% Off
12.55 Carat Pretty Loose Rubellite Tourmaline Lot For Jewellery
Located in Peshawar, PK
Loose Rubellite Tourmaline Lot Weight: 12.55 Carats Sizes: 1.80 To 4.45 Carat Origin: Afghanistan Color: Pink Certificate: On Demand Clarity: Included Rubellite tourmaline, ofte...
Rubelite, Tourmaline
13.65 Carats Rubellite Cushion Cut Top Quality For Fine Jewelry Natural Gemstone
Located in Jaipur, RJ
13.65 Carats Rubellite Cushion Cut Top Quality For Fine Jewelry Natural Gemstone Gemstone - Rubellite Weight - 13.65 Carats Shape - Cushion cut Size - 13.7x13.7x10.5 MM Pieces - 1
Rubelite, Tourmaline
$613Sale Price|29% Off
Vivid Pink Natural Rubellite Tourmaline Ring Loose Gemstone 2.30 Ct Cushion Cut
Located in Peshawar, PK
Vivid Pink Natural Rubellite Tourmaline Loose Gemstone for Ring, Necklace Pendant, Bracelet or any other Jewelry Setting-Cushion Cut from Kunar, Afghanistan!! 💎 GEMSTONE TYPE: Rube...
Rubelite, Tourmaline
15.39 Carats Rubellite Cushion Cut Top Quality For Fine Jewelry Natural Gemstone
Located in Jaipur, RJ
15.39 Carats Rubellite Cushion Cut Top Quality For Fine Jewelry Natural Gemstone Gemstone - Rubellite Weight - 15.39 Carats Shape - Cushion cut Size - 12.5x18 MM Pieces - 1
Rubelite, Tourmaline
$304Sale Price|20% Off
Pretty Loose Rubellite Tourmaline Baguette Shape Gem For Ring 0.85 Carat
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 0.85 Carats Dimension: 8.3 x 4.2 x 3.1 Mm Origin: Afghanistan Shape: Baguette Cut: Baguette Color: Pink Certificate: On Demand Rubellite tou...
Rubelite
$480Sale Price|20% Off
3.20 Carat Faceted Rubellite Tourmaline Cushion Shape Gem From Africa
Located in Peshawar, PK
Loose Rubellite Tourmaline Weight: 3.20 Carats Dimension: 10.7 x 8 x 5.1 Mm Origin: Africa Shape: Cushion Color: Pink Certificate: On Demand Rubellite tourmaline, often regarded ...
Rubelite
$240Sale Price|20% Off
3.95 Carats Natural Loose Rubellite Tourmaline Gemstone
Located in Peshawar, PK
Loose Rubellite Weight: 3.95 Carats Dimension: 10.3x9.1x5.6 Mm Origin: Africa Shape: Cushion Color: Red Treatment: Non Rubellite tourmaline is a re...
Rubelite, Tourmaline
$1,187Sale Price|30% Off
Pinkish Red Natural Rubellite Tourmaline Cushion Cut 3.24 Carat Loose Gemstone
Located in Peshawar, PK
Natural Pinkish Red Rubellite Tourmaline Cushion Cut Loose Gemstone – Faceted Earth-Mined Pinkish Red Rubellite for Statement Ring, Pendant, Custom Fine Jewelry, October Birthstone, ...
Tourmaline, Rubelite
20.02 Carat Natural Rubellite Tourmaline, Oval Cut loose gemstone
Located in Khet Bang Rak, 10
About Rubellite Rubellite is a prized variety of tourmaline, known for its vibrant pink to red tones and its ability to retain colour beautifully under different lighting conditions....
Rubelite, Tourmaline
$392Sale Price|30% Off
Reddish Pink Natural Rubellite Tourmaline Ring Loose Gemstone 3 Ct Cushion Cut
Located in Peshawar, PK
Reddish Pink Natural Rubellite Tourmaline Loose Gemstone for Ring, Necklace Pendant or any other Jewelry Setting-Cushion Cut 💎 GEMSTONE TYPE: Rubellite Tourmaline ⚖️ WEIGHT: 3.00 ...
Rubelite, Tourmaline
$280Sale Price|20% Off
3.60 Carat Natural Loose Rubellite Tourmaline Cushion Cut Gemstone
Located in Peshawar, PK
Faceted Rubellite Tourmaline Weight: 3.60 Carat Dimension : 10.2 x 7.4 x 5.9 Mm Origin: Afghanistan Colour: Pink Treatment: Non Certificate: On Customer Demand Tourmaline is a c...
Rubelite, Tourmaline, Other
$14,240Sale Price|20% Off
30.90 Carat Natural Loose Quality Rubelite Tourmaline Cushion Cut Afghan Gem
Located in Bangkok, TH
Weight 30.90 carat Dimensions 19.5x19.4x11.8mm Treatment None Origin Afghan Clarity SI Shape Cut Cushion This 30.90 Carat Natural Loose Quality Rubelite Tourmaline radiates an...
Rubelite, Tourmaline
14.40 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone
Located in Jaipur, RJ
14.40 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone Gemstone - Rubellite Tourmaline Weight - 14.40 Carats Shape - Cushion Size - 15.5x12x11 MM Pieces - 1
Rubelite, Tourmaline
$656Sale Price|20% Off
2.00 Carat Natural Loose Quality Rubelite Tourmaline Oval Cut Afghan Gemstone
Located in Bangkok, TH
Weight 2.00 carat Dimensions 8.6x6.6x5.1mm Treatment None Origin Afghan Clarity SI Shape Cut Oval This 2.00 Carat Natural Loose Rubelite Tourmaline radiates a vivid reddish-p...
Rubelite, Tourmaline
13.95 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone
Located in Jaipur, RJ
13.95 Carats Rubellite Tourmaline Cushion Cut stone For Jewelry Natural gemstone Gemstone - Rubellite Tourmaline Weight - 13.95 Carats Shape - Cushion Size - 16.5x13x9 MM Pieces - 1
Rubelite, Tourmaline