How Gold Formed in Aruba – The Role of Quartz Veins

The formation of gold deposits in Aruba was a result of millions of years of volcanic activity. During this process, minerals like quartz, iron, gold, copper, and silver crystallized within quartz veins found in Aruba’s rock formations. These veins were later mined in Miralamar, Bushiribana, and Matividiri.

How Did Gold Reach Aruba’s Quartz Veins?

Mineral Crystallization and Quartz Formation

• Different minerals formed as lava cooled. These included quartz diorite (tonalite), gabbro, hooibergite, and quartz.
• When lava solidifies at the surface, water vapor and gases escape into the atmosphere. However, when magma cools underground, these gases remain trapped.
• The metallic elements in magma only crystallize at lower temperatures, forming quartz veins.
• These veins, known locally as “Piedra di Speki”, contained small amounts of iron, gold, copper, and silver.

Gold Deposits in Aruba’s Geological Formations

1. Miralamar: Quartz veins penetrated basalt formations, making this a key gold mining site.
2. Cristalberg: Gold-rich quartz veins cut through quartz diorite in this area.
3. Bushiribana & Matividiri: Gold deposits formed within gabbro rock, leading to extensive mining operations.

These quartz veins became the foundation of Aruba’s gold mining industry, with numerous abandoned mines, locally called “bena”, still visible today.

Geological Transformations in Aruba

The Aruba Lava Formation

• 90 to 85 million years ago, Aruba’s volcanic core was folded and uplifted, reshaping the island’s terrain.
• Volcanic ash from eruptions transformed into tuff, while existing rock layers fractured due to pressure.
• In some areas, tuff underwent changes, becoming a new rock type called schist.
• The Arikok National Park region contains basalt, pillow lava, tuff, schist, and conglomerates, all formed during these geological events.

Formation of Gold-Bearing Batholiths

• As magma rose, it infiltrated the basalt layers but never reached the surface.
• The magma solidified deep underground, forming a massive rock structure known as a batholith.
• Over millions of years, quartz veins carrying gold and other minerals spread through Aruba’s geological formations.

Final Thoughts on Aruba’s Gold Formation

The gold deposits in Aruba resulted from volcanic activity, mineral crystallization, and geological shifts. This led to the discovery of gold-rich quartz veins, later mined in Miralamar, Bushiribana, and Matividiri. Today, the remnants of Aruba’s gold mines remain a testament to its fascinating geological history.