Mineralogy: Beryl and Topaz

Beryl Group

• Beryl is a mineral group that includes various colors and varieties, such as Aquamarine, Morganite, Red Beryl, Yellow Beryl, and Green Beryl.

Topaz

• Topaz is a mineral that can be colorless, red, pink, purple, yellow, orange, and brown, as well as blue and green.
• Imperial Topaz is the most valuable, with a medium reddish orange to orange-red color.
• Red Topaz is rare and highly cherished, while pink topaz resembles pink diamond.
• Golden or yellow topaz are the least valuable.

Crystal Structure

• Topaz has an orthorhombic crystal system, typically elongated with strong parallel grooves or striations.
• Aquamarine has a typically six-sided columns with flat faces at their ends, with crystals ranging from very small to very large (up to 45 kg or 100 lbs).

Possible Phenomena

• Aquamarine can exhibit pleochroism, showing near-colorless and strong blue in different crystal directions.
• Morganite (Pink Beryl) displays distinct pleochroism, with pale pink and deeper violetish pink colors.
• Red Beryl is pleochroic, with shades of purplish red to red to orangy red.

Treatments

• Topaz is often heat-treated or irradiated to create or change colors, such as turning yellow to reddish topaz into a salmon to purple-red color.
• Aquamarine is often heat-treated to remove yellow, resulting in a pure blue color.
• Morganite (Pink Beryl) is heat-treated and irradiated to enhance its color.

Countries of Origin

• Topaz is mined in Brazil, Pakistan, Sri Lanka, Australia, Madagascar, Mexico, Myanmar, Namibia, Nigeria, and the US.
• Aquamarine is primarily sourced from Brazil, Pakistan, Australia, Vietnam, Kenya, Madagascar, Mozambique, Nigeria, the US, and Zambia.
• Morganite (Pink Beryl) is mainly sourced from Brazil, Afghanistan, Mozambique, Namibia, and the US.

Common Cuts

• Topaz is often cut into oval, pear, and emerald shapes due to its elongated crystal structure.
• Aquamarine is often cut into emerald or round brilliant shapes, with fancy cuts and ornamental shapes.
• Red Beryl is typically cut into melee sizes, with an average faceted size of 0.15 ct.

Clarity Characteristics

• Aquamarine is often eye-clean, but can have liquid inclusions.
• Red Beryl often has fingerprint and two-phase inclusions, unhealed fractures, solid crystal inclusions, distinct color zoning, and growth features.
• Yellow Beryl is typically eye-clean.

Synthetic Process

• Aquamarine is hydrothermally synthesized in Russia.
• Morganite (Pink Beryl) is hydrothermally synthesized in Russia.

Imitation Materials

• Aquamarine is often imitated with treated blue topaz, pale blue glass, and synthetic blue spinel colored by cobalt.

Trade Names

• "Rose Topaz" is used for pink topaz, while "Sherry Topaz" refers to orange-to-yellow to brown topaz.
• "Cyclamen pink" is a violet-pink topaz from Pakistan.
• Red Beryl is also known as "red emerald", "bixbite", and "raspberry red".
• Yellow/Golden Beryl is also known as "heliodor".