As exceptional material becomes increasingly difficult to source, these gemstones continue to be admired by collectors and connoisseurs around the world.

From beautifully hand-cut old mine diamonds to the unmistakable glow of Paraiba tourmaline, velvety Kashmir sapphires and vivid natural spinels, these are some of the world's most fascinating collector gemstones, each with its own remarkable story to tell.

• Brazilian Paraiba Tourmaline – The story of Paraíba tourmaline began in the hills of Paraíba, Brazil, where miner Heitor Dimas Barbosa spent years searching for a gemstone he believed lay hidden beneath the earth. In 1989, his determination was rewarded with the discovery of a vivid copper-bearing tourmaline unlike anything the world had seen before. Its electric colour transformed the coloured gemstone market almost overnight, and the limited yield from the original Brazilian deposits has made exceptional stones among the most valuable and sought-after by collectors today.
  

• Paraiba-Type (Cuprian) Tourmaline – Copper-bearing tourmalines from Mozambique and Nigeria share the same remarkable chemistry and vibrant glow as the Brazilian originals. As genuine Brazilian Paraíba tourmalines have become increasingly scarce, these beautiful gemstones have become highly desirable in their own right, offering collectors exceptional colour at a more accessible price point.
  
• New Discoveries – Ethiopia has also produced promising copper-bearing tourmalines in recent years, adding another exciting source for collectors to watch as the story of this extraordinary gemstone continues to evolve.
  
  

• Kashmir Sapphire – Mined between the 1880s and 1930s, Kashmir sapphires are famed for their velvety cornflower blue colour. With the mines now largely exhausted, genuine Kashmir stones are exceptionally rare and command some of the highest prices of any sapphire.

• Royal Blue Sapphire – The classic sapphire colour, prized for its rich, vivid blue and timeless appeal. Fine natural examples remain among the most sought-after gemstones in the world.

• Lilac Sapphire – A softer, more unusual variety with delicate violet-lilac tones, perfect for collectors looking for something distinctive and less traditional.

• Soft Yellow Sapphire – Elegant and understated, yellow sapphires have grown in popularity thanks to their warm, sunny colour and versatility in jewellery.

• Padparadscha Sapphire – One of the rarest sapphire varieties, recognised for its delicate blend of pink and orange. Named after the Sinhalese word for the lotus blossom, it has long been associated with Sri Lanka and is highly prized by collectors.

Treatments

• Heat Treatment – Heat treatment is common market practice and widely accepted within the jewellery industry. However, untreated ("no heat") sapphires are considerably rarer and command a significant premium. They should be accompanied by certification from respected laboratories. Heat treatment can help improve colour and disperse certain inclusions and even remove 'silk like inclusions'
• Beryllium Treatment – A diffusion process used to enhance or introduce colour, particularly in orange and yellow sapphires. While acceptable when fully disclosed, these stones are generally considered far less desirable than naturally coloured or untreated sapphires and as a gemstone collector these are to be avoided.

• Tsavorite Garnet – An intensely green garnet discovered in Kenya and Tanzania during the late 1960s by geologist Campbell R. Bridges and named after Tsavo National Park. Its vivid green colour comes naturally from vanadium and chromium, and unlike emerald, it is typically untreated. Rough is rarely found in large sizes, making stones over two carats especially collectible.

• Demantoid Garnet – A rare green garnet historically mined in Russia's Ural Mountains, renowned for its exceptional fire, even greater than that of diamond. Collectors look for the distinctive "horsetail" inclusions, which are considered a mark of quality and Russian origin rather than a flaw.

• Red Spinel – Historically mistaken for ruby, several famous "rubies" in royal crown jewels, including the Black Prince's Ruby in the British Crown Jewels, are actually spinel. Fine red spinels, particularly from Burma, are among the most sought-after varieties.
• Mahenge Spinel – Discovered in Tanzania, Mahenge spinels are celebrated for their extraordinary neon pink colour and have become one of the most desirable collector gemstones in recent years.
• Blue & Lilac Spinel – Cobalt blue and delicate lilac spinels are increasingly popular for their vibrant, natural colour and exceptional rarity.
• Natural Beauty – Unlike many coloured gemstones, fine spinels are rarely treated, making their remarkable colours entirely natural, one of the many reasons they have become so popular with collectors.