xUmp.com Logo

TODAY'S COUPON: SAVE ADDITIONAL 8% OFF with coupon code: SAVE8 [Expires tonight at 11:59PM. Online orders only.]
Black Tourmaline - Large Chunk (2-3 inch) - Image One
Share this product:

Black Tourmaline - Large Chunk (2-3 inch)

Item#: 15748  
List Price:$15.99
Sale Price: $10.99 /each
You Save: $5.00 (31%)
SOLD OUT Check back in 5 to 10 days to order this item.

This large chunk of Black Tourmaline, 2-3 inches in diameter, is great for any mineral collection.

In its natural state, all Tourmalines are characterized by parallel ridges (striations) which run the length of the crystal. Tourmaline forms in igneous and metamorphic rocks and veins, and have a different shaped top than the bottom of the crystal. Another interesting characteristic is that this stone is a pyroelectric which means that when heated, a positive charge develops at one end and a negative charge at the other.

FOUND IN: TANZANIA, MADAGASCAR, BRAZIL, AUSTRALIA, SRI LANKA, RUSSIA & USA

Tourmaline’s name comes from the Sinhalese word “turmali,” which means “mixed.” Tourmaline, occurring in more colors and combinations of colors than any other gemstone variety, lives up to its name. Known for centuries, tourmaline first gained popularity when the Dutch began to import it in the early 17th century from Sri Lanka . Tourmaline is actually the name of a group of related mineral species. In gemological practice, individual species names are not used. Instead, all are simply termed tourmaline.

Color is the major characteristic for tourmaline. This stone is found in more hues, shades and nuances than any other gem.

Black Tourmaline Specifications:

  • Moh’s hardness: 7 – 7½
  • Specific gravity: 3.02 – 3.24
  • Cleavage: None
  • Fracture: Uneven, Small Conchoidal, Brittle
  • Crystal system: Hexagonal (Trigonal)
  • Chemical composition: SiO2 silicon dioxide (NaLica) (Fe11 Mg MN Al) Al ((OH) (BO) Si6 O18)
  • Refractive index: 1.554 – 1.553
  • Double refraction: -0.014 to -0.044
  • Dispersion: 0.017


Age:
14 +
Box Size:
3.00 x 3.00 x 3.00 inches
7.62cm x 7.62cm x 7.62cm
Weight:
0 lb 10 oz
0.28 kg

Customer Reviews


There are no customer reviews for this product. Be the first one to write one!

FEATURED PRODUCTS

Space Wonder Gyroscope.

$9.99

Space Wonder Gyroscope

This high precision gyroscope will amaze you with rotational speed and ease of precision.

Wilderness Survival Playing Cards.

$6.99

Wilderness Survival Playing Cards

Ever wonder how to survive in the wilderness? These cards can help!

Brush Robot 4M Kit.

$15.99

Brush Robot 4M Kit

Get swept away by this fantastic robot kit that uses vibrations to move!

Genetics & DNA Kit.

$34.99

Genetics & DNA Kit

Head into the lab for an in-depth investigation of genetics and DNA!

MuscleWires Monster Moving Hand Kit.

$29.99

MuscleWires Monster Moving Hand Kit

Build a hand that realistically moves its fingers using shape memory allow technology!

Temperature Controlled Soldering Station.

$29.99

Temperature Controlled Soldering Station

Use this temperature-controlled soldering station for a variety of soldering applications!

xUmp.com Logo


Join our tribe:

SIGN-UP & SAVE

Sign-up for our weekly discounts and promotions email newsletter.



xUmp.com Catalog

CATALOG

View xUmp science supplies catalog

xUmp.com Mission