Definition

Noun: 1. A black variety of the mineral tourmaline: Schorl is the most common and widely occurring form of tourmaline, characterized by its opaque, deep black color and prismatic crystals. It is a complex borosilicate mineral.

Examples of Usage

• Noun:
  • The geologist identified the black, striated crystal in the granite pegmatite as schorl.
  • This specimen contains both clear quartz and needles of black schorl.
  • Schorl is often found in association with other minerals like feldspar and mica.

Advanced Usage

• In mineralogy and geology: The term is used specifically to denote the iron-rich, black endmember of the tourmaline group. It is distinguished from other colored tourmalines (such as elbaite, which can be pink, green, or blue) by its composition and color.
  • The chemical formula for schorl is NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄.

Variants and Related Words

• Tourmaline (n): The name of the broader mineral group to which schorl belongs. Tourmaline encompasses many varieties with different colors and chemical compositions.
  • While schorl is black, other forms of tourmaline can be virtually any color.

Synonyms

• Black tourmaline: This is a direct descriptive synonym commonly used in gemology and mineral collecting.

Notes on Different Meanings

• The word "schorl" has a single, specific meaning in mineralogy. It does not have multiple common definitions outside of this scientific context. It refers exclusively to the black, iron-bearing variety of tourmaline.

Noun

1. black tourmaline