Black Tourmaline

Mineral Group: Tourmaline Group

Key Properties

Property Value
Mohs Hardness 7.25 (7-7.5)
Typical Size 1-50 carats (commercial: 2-20 carats; large sizes available, rarely faceted)
Typical Price Range $5-30 per carat (commercial: $10-20; limited jewelry demand)
Rarity Level Abundant Minerals
Availability Level Consistently Available
Availability Driver Consistent Deposits
Investment Appropriateness Non-Investment Gems

Detailed Descriptions

Rarity Description: Iron-rich tourmaline (schorl); one of the most common tourmaline varieties found in pegmatites worldwide.

Availability Description: Very common as mineral specimens and in metaphysical markets; occasionally used in mourning jewelry or as accent stones.

Investment Description: Extremely common schorl variety; primarily mineral specimen and metaphysical markets; no jewelry or investment value due to abundance and low desirability.

Colors

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Investment Ranking Calculation

The composite score of 16.25 is calculated using a weighted formula:

  • Geological Rarity (25%): 35 points
  • Market Availability (25%): 10 points
  • Investment Appropriateness (25%): 5 points
  • Hardness (12.5%): 25 points
  • Price Range (12.5%): 5 points

Formula: (35 × 0.25) + (10 × 0.25) + (5 × 0.25) + (25 × 0.125) + (5 × 0.125) = 16.25

VERY BEARISH
16.25

Score Components

Geo rarity
35
Mkt availability
10
Invest Appr
5
hardness
25
price
5