Antique Gemstone Guides: Sapphire, Emerald, Opal

Tiffany T circle pendant in 18k yellow gold with a round polished turquoise inlay framed by small diamonds and an open T motif, on a fine gold chain.

October 2026

How to Tell If Turquoise Is Real: Dyed Howlite, Stabilised Stone and Block

How to tell if turquoise is real: the drill-hole check that exposes dyed howlite and magnesite, what stabilised, enhanced and block turquoise...

Loose cut coloured gemstones, including blue, green, red, purple and yellow stones, on an antique silver tray and green velvet beside a loupe, tweezers and a notebook of cut diagrams.

October 2026

Aquamarine vs Blue Topaz: How to Tell Them Apart

Aquamarine vs blue topaz: why one is iron-coloured beryl and the other usually irradiated topaz, how density, refractive index and dichroism separate...

Loose cut gemstones including an emerald, rubies, blue sapphires and purple and yellow stones on an antique silver tray and green velvet, with a loupe, tweezers and a notebook of cut diagrams.

October 2026

Synthetic Rubies Since 1902: The Lab Stones Hiding in Antique Rings

Synthetic rubies have been made since Verneuil's flame-fusion process of 1902, and many Edwardian, Art Deco and 1940s rubies are lab-grown. How...

Loose sapphire, ruby, emerald, citrine and amethyst gemstones on an antique tray with tweezers, a jeweler's loupe and cut diagrams.

October 2026

Padparadscha, Pink and Yellow Sapphires: The Colours Beyond Blue

Fancy sapphires explained: padparadscha, pink, yellow, orange, purple, green, white, colour-change and parti sapphires, where each comes from, how they are treated,...

Imperial Russian ring with three blue sapphires and old cut diamonds, bezel-set in hand-engraved 14k gold, front view.

October 2026

Tanzanite vs Sapphire: How to Tell Them Apart, and Which Lasts

Tanzanite vs sapphire: zoisite from Tanzania's Merelani Hills against corundum, how to tell them apart by colour and refractive index, heat treatment,...

Loose emerald, ruby, sapphire, citrine and amethyst gemstones on an antique tray with tweezers, a loupe and gemstone cut diagrams.

October 2026

Alexandrite: The Colour-Change Gem of the Tsars, and How to Spot a Fake

Alexandrite explained: the colour-change chrysoberyl from the Urals, why it turns green to red, Brazilian and Sri Lankan sources, synthetic alexandrite and...

Loose ruby, emerald, sapphire, citrine and amethyst gemstones on an antique tray with tweezers, a loupe and cut diagrams.

October 2026

Ruby Buying Guide: Pigeon's Blood, Origin, Heat and Glass-Filled Rubies

Ruby buying guide: what makes a ruby valuable, what pigeon's blood really means, origins from Myanmar to Mozambique, heated, flux-healed and glass-filled...

Loose emerald, ruby, sapphire, citrine and amethyst gemstones on an antique tray beside tweezers, a jeweler's loupe and gem cut diagrams.

October 2026

Birthstones by Month: The Full List, What Each Means, and the Antique Versions

Birthstones by month: the full modern list and its alternatives, the 1912 origins and later additions such as tanzanite and spinel, traditional...

Loose emerald, ruby, sapphire, citrine and amethyst gemstones on an antique tray with tweezers, a loupe and cut diagrams.

October 2026

How to Tell If a Gemstone Is Real or Glass: Rubies, Sapphires, Emeralds

How to tell if a ruby, sapphire or emerald is real, glass, synthetic or a doublet. The loupe signs that give imitations...